It’s just trivially easy with electric thanks to regen braking.

Though with modern cars getting heavier if you have a small ICE these days you have almost no engine brake which makes some cases more difficult (unless it’s a mild hybrid with an electric kers like some of the small engined fords). SUVs tend to have giant engines and pretty high rolling resistance, which I’d think would somewhat compensated for their higher inertia.

It’s all about learning your car’s behaviour and planning for it.

You can do it in an automatic, you just have to force it to select a lower gear using the gear number options (1, 2, 3, 4) or using the tiptronic mode. The lower gear means the engine will displace more air in the same amount of time, increasing the rate it pulls energy from the wheels.

People think you can't do it in automatics because they try very hard to keep engine RPM low where the effect is diminished.

If you release the compressed air without pushing the cylinder down you would lose that energy, but you would need a extra device to do so (by lifting a valve at the right time). This option does exist for large vehicles like trucks as a compression release engine break [0], but this isn't something you'd have on a family car.

In a petrol engine you always want the same ratio of petrol to air in the mix that is taken into a cylinder. As you want to vary the amount of fuel, and therefore power developed, you have to be able to therefore limit the amount of air that is sucked in. Otherwise the engine would always run at full power.

There is a mechanical restrictor called a throttle plate that lives inside the throttle body that restricts how much air the cylinder can pull in (and therefore how much fuel is injected to get the same fuel/air mix). This is controlled by the throttle. When you are coasting, this plate is in its most closed position. This creates significant resistance on the intake stroke, and is where the majority of energy is lost during engine breaking. This is also known as a pumping loss.

Diesels always intake the same amount of air, so they can compress it enough to autoignite the fuel. They vary the amount of fuel injected to the same volume of air. This means no throttle body or plate, so unless an extra exhaust restrictor has been added there is minimal engine braking on a diesel engine.

[0] https://en.wikipedia.org/wiki/Compression_release_engine_bra...

Though the ECU would be doing the AFR management on modern EFI engines as the injectors aren't vacuum operated like Carburetors were. You should be able to cut fuel injection when coasting in a modern engine, can't run lean if there's no fuel at all. Not sure if carbs could do the same.

More modern engines have electronically controlled throttle plates, and this is definitely somewhere you could do something clever like you suggest - cutting fuel flow but also maximising airflow when there is zero throttle input.

I assume engine braking is generally considered a beneficial thing by manufacturers, but it could be fun to be able to customise the amount. Or do something like have the braking come on gently at first then harder. Maybe even try and have a linear or flat response curve vs. engine rpm.

Some recentish motorbikes have an option to customise the amount of engine brake, I suppose cars could have something similar, too.

You can do this by letting go of gas pedal slowly. I have "current amount of fuel used" info in my car (liters/100km), it shows pretty clearly, that when going fast and slowly letting go of gas, amount of fuels slowly goes to 0. If I let go of gas fast, the engine is intelligent enough to not close throttle as fast as possible, still probably takes 1 second.

> More modern engines have electronically controlled throttle plates, and this is definitely somewhere you could do something clever like you suggest - cutting fuel flow but also maximising airflow when there is zero throttle input.

They cut fuel flow and close throttle plate almost completely but still allow some small amount of air, in order to actually do engine braking. If you need to coast, you can apply clutch in manual. Don't know that much about automatic, but from what I've driven, they use "lift gas" as a "engine braking" signal, so probably they can't really coast that good.

Funny because the cars build dates are only 2 years apart, 2005 and 2007, and they're both K20 engines but the engines handle so different.

The OEMs try real hard to prevent this because the amounts of emissions byproducts that aren't water or C02 they're allowed to produce are on the order of single digit grams per multiple miles (you can mentally file it as "about the baseline air quality in urban areas" though the rules are hugely more complex than that) so these edge cases matter.

You don't want to do this. Much of the engine braking effect is from pulling the intake air charge past the mostly closed throttle plate. On a car with a wide open throttle plate [even with no fuel], the engine is acting more like a spring than a damper. On the intake stroke, it will pull an intake air charge past the small restriction of the open intake valve(s), then compress it on the compression stroke, then release that compressed energy on the "power" stroke, then exhaust it past the small restriction of the open exhaust valves. Pushing air past the valves will cost energy, but it's not much.

This is why diesel trucks' engine braking works differently. (Diesels don't have a throttle plate.) They can open the exhaust valves to prevent the energy recovery in the "power" stroke to create a higher net braking force. Jake Brake: https://en.wikipedia.org/wiki/Compression_release_engine_bra...

It's basically like an air compressor that just keeps running despite hitting max pressure and every pump just goes out the blow off valve.

Toyota Sienna 2015 - the braking effect is unfortunately minor.

Using the numbered gear options will enable clutches/bands that provide more engine braking.

For example, if I brake somewhat hard from 130 km/h to 90, it will downshift from 6th to 5th. When riding normally, it would stay in 6th down to around 50.

Most automatic transmissions don't handle downshifts like manual, even the tiptronics. There's a delay, or it briefly goes neutral, or it doesn't rev-match well. Or you can't double/triple-downshift, which is worse when you have 8-12 gears. Allegedly wears them down faster too, which idk, but it certainly doesn't seem happy.

Hence Quattroportes eating clutches like nobody’s business while the harder-ridden higher-power Ferraris don’t.

As such downshifting would not wear clutches much.

And anecdotally I’ve never suffered from or heard of engine braking causing clutch issues.

Idk how the Ferraris are different. They're lighter at least. Think they also have a different version of the "Superfast" software.

And I do engine-brake, it helps cause the car is heavy and would normally wear out the brakes kinda fast.

I've never driven an automatic Ferrari or paddle shifted Ferrari to compare, but the QP that I drove (Ferrari V-8, I think that it even said Ferrari on the valve covers maybe) didn't have anything outstanding about the transmission that I remember. I thought it was a regular hydraulic automatic with a torque converter, so they really did tune it nicely. The robotic Toyotas I could feel. Maybe had they not tuned it so nicely it might have lasted longer?

Also, I have never ever had to replace a clutch, and I drive my cars way past 100k miles.

If your comment wasn't meant to imply that engine braking wears the clutch more than normal gearing, if you just want to avoid gear changes as much as possible, disregard this comment. (Although... I'm not sure that that's a valid worry, modern clutches last a LONG time when used properly)

You don't make it slip when shifting gear.

It wears the clutch but clutch wear is massively dominated by starts from a stop or other cases where you actively slip it any noteworthy amount so just rowing the gears up and down doesn't do much.

Not saying it's smart but when predictably decelerating on the highway I sometimes shift gears by rev matching and changing without even touching the clutch, for the fun of it.

I’d wager bordering on 100% of my clutch use is when coming to a complete stop.

This seems a bit exaggerated. Staying regenerative-only does require sticking to about half or so of how fast I could stop, but so far that seems to work fine unless a light turns right in front of me or traffic acts up. Usually it says it gets high 90's or 100%, and it didn't go below 50% even when a stoplight did turn at exactly the wrong time. (2022 Ford Escape non-plug-in hybrid, recently bought used.)

Bigger battery is more capacity sure. But their point was that even without a big battery they have enough capacity to get close to maximum effectiveness, contrary to ajross saying that a hybrid's capacity is "not really" effective and "at best" helps "some".

braking system = circa 1G of deceleration possible (depending on tyres, coeff of friction, temperature, ... etc etc)

So max effectiveness is unreachable for any regen system on a consumer car hybrid or ev, by a factor of around 6x i believe?

With recognition of the mistaken framing (near max effectiveness) we're back to the larger ev pack has a greater ability to sink current, a larger ability to slow the vehicle than does a smaller battery (obvious considerations about inverter capability, wire gauge etc etc aside)

Their definition of effectiveness is the percentage of braking force that turns back into electricity and goes into the battery. If your regen system can only do .15G, but 90% of your braking is under .15G, then you'll have about 94% effectiveness by that definition. 94% is not max but it's near max.

It's not about what happens during peak braking, it's about what happens over entire drives.

And when they say "half or so of how fast I could stop" they're underestimating, that's a comparison to a normal but aggressive stop, not pushing the pedal into the ground.

It's NOT relevant to overall (tyre, brake system & engine braking & regen braking) braking system performance since that's a dynamic value variable over many factors constantly.

Every other EVs and HVs assign first half of brake pedal for regen and bottom half for mechanical brakes. Tesla uses bottom half of gas pedal for the same, which eliminates the need to accurately determine the appropriate pedal force that corresponds to intended braking force to be added up with regen to match intended deceleration. Mapping regen to gas is `set_motor_torque(1.25 * gas_pedal - 25);` and that's much simpler.

And it's not a problem when you get used to regenerative-only braking distances, which are surprisingly long at highway speeds.

It only becomes a problem when idiots thinking "the shorter the distance between first and last car, the smaller the traffic" start cutting you off when you leave enough distance for regenerative braking.

Your very old tires makes you a serious threat on the road while completely oblivious about this fact... not cool, please change them if you drive on public roads, if not for you just for the sake of others.

I just trashed some 15yo Firestones last month, after wearing them completely bald of course.

My manual car could do this 20 years ago. My fully ICE motorcycle can do it today.

I know engine braking is cool but it’s not some amazing new thing only EVs can do. Altho granted it only produces heat and noise in petrol vehicles. But it also makes your heart sing so that’s nice

With an EV I don't touch breaks unless in situations I fail to/couldn't predict (maybe up to 10% of all speed reductions and even less stops).

Oh all the time. I used to drive like a typical youth. I've been in USA for 10 years now and still hate driving automatics because they shift into too high a gear and then you have to constantly use the brakes. It's annoying.

A lot of CVTs have virtual gears for that even, although others like the prius only have B mode.

     2 kWh for the drivetrain
   809  Wh regenerated

     2 kWh for the drivetrain
   547  Wh regenerated

I'm mostly happy about that but there is one thing that annoys me. 33% is close to how much a kilometer is shorter than a mile (38%).

Why the fuck would I care that these two numbers are that close? It is because of a mystery in the Hyundai app. When you look up the trip details for an EV trip it gives you mileage, duration, and energy use (drivetrain, climate, accessories) and regeneration.

The mileage is substantially less than what the car shows. For example for the aforementioned trip home that trip odometer shows 8.0 miles but the Hyundai app shows 5 miles. The car odometer has the correct distance.

There are two theories to explain this.

1. The app is showing how many miles worth of energy you used rather than your actual trip mileage. All the other data it shows (except for the duration) is energy related. For my 8.0 mile trip I got 3 miles worth of the energy the drivetrain used back via regeneration, so I only actually paid for 5 miles worth of electricity.

Based on the Wh given it should actually be 5.4 miles, but the app only displays integer mileage so 5 it is.

2. It's a botched unit conversion. E.g., the car uploads the data in miles but the expects the data to be in km, so it is doing a conversion. That would turn the 8.0 into 5.0, which would be 5 in the app and so matches what theory #1 predicts.

I've checked several of my trips and they have always happened to have the right amount of regeneration so that the two theories match due to the app only showing an integer mileage.

I did a test today to try to tell them apart. I changed the car's settings to km and took a trip. The idea was if the car had been uploading in miles that would hopefully change it to upload in km, matching the app's expectation, and so the miles shown in the app would match the actual miles of the trip if theory #2 was correct, and show the regeneration corrected miles if theory #1 was correct.

The result was that the app still showed miles consistent with theory #1. So mystery solved, right?

Maybe not. When the car was set to miles everything showed in miles. Speedometer, odometers, efficiency (mi/kWh), speed limits it read from traffic signs, and speed limits it gets from the map data when using navigation on highways.

I expected than when I switched it to km all of those would be in km, and I would not see miles anywhere. Also, I expected that when it saw a speed limit sign that said say 60 it would interpret that as 60 km/hr.

What actually happened is that miles mostly did go away, except on the speedometer it added a smaller mi/hr display under the km/hr display. For the traffic signs it still knew they were in mi/hr and it converted them, so when I got on the freeway as soon as I passed the sign that said 60 the speed limit sign shown on the instrument cluster said 97, and the red dot on the speedometer showing the current limit was placed in the right place.

That suggests that the car knows it is in a country that uses miles, and doesn't just go by whatever the units setting in the setup screen is set to. It could be that in miles countries the car also uploads in miles all the time, and so switching the units setting to km would not change the results if theory #2 was true.

Now my plan is to find a big parking lot that is mostly empty overnight, such at a Walmart or Home Depot or a mall, go there and turn the car off and then back on which starts a new trip, set regeneration to 0 which turns off automatic regeneration on the accelerator so the car only regenerates when you use the brake pedal, and then drive around the parking lot for about 10 miles without using the brakes, then coast to a stop and turn the car off the end the trip.

Then I'll turn it back on, drive home, and check the trip details in the app. If theory #1 is right then the miles in the app should match the odometer miles. If theory #2 is correct the app miles should still be 38% shorter than the odometer miles.

Are you comparing to an automatic ICE or a manual?

In my experience of driving EVs their engine braking is sub-par to what I'm used to at least from my motorcycle. Bikes have silly high compression compared to their weight. You def have to be careful about chopping the throttle.

And I mean if drifters can use shift lock to literally skid their wheels, then clearly engine braking is effective.

Also I learned in driving school in Europe (and during the motorcycle course in USA) to downshift while braking so your engine helps the brakes and you’re always in the right gear. There shouldn’t be any sudden revs if you’re gentle with the clutch.

Then again as a young idiot I also learned how to heel-and-toe on public roads so I could rev match more effectively while braking into corners. Maybe I’m just a weird driver with unusual habits. It’s ok.

I also like the noise, but it is noise pollution that is very annoying to everyone else.

Hybrid makers just don't really care about that.

(They also don't do blending between friction brakes and regen, so the cars behaviour when letting of the accelerator is highly inconsistent depending on temperature and charge level).

One of the reasons I long for the lease on my Model Y to end so I can replace it with a less stupid vehicle.

Many thousands kilometers later I hate it almost as much as at the start, so lack of regen configuration will be a dealbreaker next time I pick a new car.

1. It is inconsistent, especially during winter and when fully charged.

2. Crossings with shrubbery/objects that hides approaching pedestrians/cars/bikes and it is rare that there is anyone actually crossing. I encounter these several times per day.

My preferred way of approaching #2 is to reduce speed well ahead, start gliding and put my foot on the break pedal to be ready for a complete halt in the rare case (once in a 500 maybe) that I need to give way to someone. In the Tesla I must reduce speed to almost standstill and creep slooooowly, since it would take half a second to move the right foot to the break.

I understand it sounds like an extreme corner case, but for me it is all the time every day. Central Scandinavia.

I want my right foot on the break pedal, ready to brake hard and fast in the rare case that something comes across the road.

I don't want to reduce speed any further than is necessary to have a safe breaking distance at fully ready state.

With any other car (that I have driven) than the Tesla, I can approach a situation like this at between 20kmh and 40kmh, depending on the specifics. In the Tesla I need to go at between 5 and 10kmh.

I generally turn off the auto regen braking because i find it uncomfortable.

Importantly, regenerative braking is a danger on icy roads. I disable it entirely in the winter in eastern Canada because it often causes the tires to lose grip.

They didn't care much for convential wisdom and car building competence in the early days of Tesla.

The key takeaway is that there are differences to driving an EV to driving an ICE vehicle. Equally those differences are in fact easy to adjust to given a bit of practice.

Of course cars have always had different control options. Automatic and Manual gearboxes spring to mind. When I first learned some cars had a gear selector as an arm on the steering column, and so on.

EVs like a somewhat gentler foot, because the torque is instant, so a heavy foot is likely to be a more uncomfortable ride.

So yes, different cars, different styles. But of course we adjust very quickly, and its not really difficult to drive anything- it just takes a bit of practice.

All to say, check out a few to be sure, im still shocked how much i love driving this thing (and how criminally fast it is, totally absurd).

Are you not? Do you drive by blipping the gas every few seconds?

I've had Uber drivers do this and it is annoying bordering on nauseating as a passenger. It is probably pretty bad for mileage and transmission wear as well (constantly taking up and releasing the backlash in the gears).

Secondly, I rented an EV for a week and by the end of it actually preferred the strong regen setting. It was convenient in stop-start traffic, and on a twisty road, you could use it to tighten the nose as you entered the corner.

> was difficult to get used to

To ask the obvious, how used to something are you going to get on a test drive? It takes time.

For example here is how it works in Hyundai EVs (and I'd guess Kia too). It is easy to set them so that they drive very similar to an ICE. I believe several others also work similarly. There are only a few that try to really push you to one pedal driving.

1. When use explicitly use the brake pedal that car uses regenerative braking unless you are trying to stop faster than regeneration can handle in which case it will also use the friction brakes.

There may be a setting somewhere in the settings menus where you can adjust how strong the braking is, but I don't remember because the way the car comes from the factory the brake peddle feels a lot like an ICE car's brake peddle.

2. There is a regeneration level setting that controls what happens when you ease up on the accelerator or remove your foot from it. This setting has 6 possible settings: Level 0, 1, 2, 3, i-Pedal, and Auto.

There are two paddles on the steering wheel that let you move through these settings quickly and easily, and you can do this while driving so you are free to pick whatever setting fits the conditions and your mood the best. Here's what they do.

• In level 0 there is no braking associated with the accelerator. Take your foot off and the car coasts is if it was in neutral.

• Level 1 provides a small amount of automatic braking when you let up on the accelerator. In ICE terms it is similar to the engine braking you would get on level ground going fast enough to be in 3rd gear in a 3 speed automatic. You slow down faster than coasting, but not so fast that if you were on the freeway and your felt the need to shake your right leg around a little it would slow enough to be a problem.

• Levels 2 and 3 step up the amount of automatic braking. 3 is enough that in city driving most of the time you can be quite leisurely when it comes to moving your foot from the accelerator to the brake at most stop signs, but it will not bring your car to a complete stop. It will get quite slow and then creep at that speed.

• i-Pedal is one pedal driving mode and corresponds to what that EV you test drove was doing. In this the braking is similar to level 3 as far as aggressiveness goes, but it will take you all the way to a stop most of the time. Once you get used to it you should be able to do most city driving and most highway driving without touching the brake pedal. About the only times you would need the brake pedal (outside of emergencies) is if a light changes on you when you are too close to the intersection.

• Auto mode automatically switches between 0, 1, 2, and 3 based on the distance to the vehicle in front (using the same system that adaptive cruise control uses) and the slope of the road. If you are on the freeway for example with a good distance between cars it will be in 0 or 1. In the city where you are close to the next car it might be in 2 or 3.

• If you press and hold the "increase regen level" paddle for at least 0.5 seconds it will switch from whatever your current setting is to i-Pedal and stay in i-Pedal as long as you continue to hold the paddle. Release the paddle and it switches back to whatever your previous setting was.

This system gives you plenty of flexibility and you should be able to easily find a setting you like. Some people really like one pedal driving and so they can just put it in i-Pedal and leave it there (with a slight annoyance...when you turn the car off in i-Pedal it comes back on in level 3, so you will have to hit the regen up paddle once).

Some people set it to one of the numbered levels and leave it there (again with slight annoyance at startup where it comes on at 1 so they need a paddle flick or two).

Some people use the paddles instead of the brake pedal, mixing levels to get the kind of deceleration curve they want.

I normally drive in level 0, with an occasional day or two in i-Pedal just for a change of pace, but if I'm coming up on a series of roundabouts I might switch it to i-Pedal. That's great for say a 35 mph road with 10-15 mph roundabouts every couple of blocks. (If it is just one roundabout I'd probably use the "hold regen up paddle for 0.5 seconds" option to just turn on i-Pedal for that intersection.

Part of the point, not the whole point. Regenerative breaking is absolutely a win; but there can also be a significant benefit from allowing the ICE to remain in the RPM "sweet spot" rather than moving around a larger range.

But then, do you end up removing enough battery weight to offset the weight of a whole ICE?

Toyota is the biggest seller of HEV's, Stellantis of PHEV. That's the difference. EV's on paper should be the most reliable, but Tesla is the biggest seller of those. If you want reliability, choose by brand rather than engine type.

Mostly issues with 12V battery, it seemed like.

In the end I bought a Stellantis EV so I probably deserve everything I get - but they are cheap!

Eh, it's not so much nonsensical, as it is that you're just misinterpreting the data.

This conversation here is specifically about powertrain reliability, but that isn't what consumer reports measures. They measure complaints about any feature on the vehicle, including ancillary accessories unrelated to the vehicle's ability to transport people.

But also as you point out, shitty engineering (Stellantis's specialty) is a bigger issue than any particular drivetrain type.

Just think - if two drivetrains were less reliable, wouldn't you see that with the Prius?

On the other hand, a Toyota hybrid doesn’t have a gearbox at all, not even a CVT. Instead it has something similar to a differential, it’s mechanically simple and very reliable. It uses the electric motor in place of a turbo, so that’s another common failure point removed. It doesn’t have a starter motor, and the Atkinson cycle engine should suffer less stress than an equivalent petrol.

Practically the biggest problem is finding a 3rd party garage who will inspect the hybrid parts as part of a service.

Commercial aviation is a great example of taming extreme inherent unsafety of aircraft by applying a lot of resources to the engineering side. Another is space programs.

And car power trains have nothing on those ;) As Toyota has shown, it's totally possible to make reliable hybrid cars with enough engineering thrown at the problem.

So if all things were equal, you'd absolutely expect an EV to be more reliable than a hybrid, but all things are rarely equal.

I hate to break it to you but something like a Rogue or HRV does circles around an Altima or Civic when it comes to daily flexibility and utility for a fairly paltry additional cost. It doesn't take a degree in rocket surgery to figure out why they fly off the shelves. For the average person they're a good combination of attributes.

A practical car is a station wagon, not an SUV, many of which have less storage space.

Please, cut the needless snark. People do buy vehicles for edge cases but the lack of smaller, practical vehicles is driven is large part by manufacturer profit.

I agree that there's a lot of stupidity going on when it comes to station wagons vs crossovers vs compact SUVs and the OEMs really do SUV-ify a lot of things that ought not to be.

The shape of these vehicles is fairly preordained by the nature of the fuel economy regulations and wind resistance and other regulations that apply equally to all of them. You're not gonna find "more space" in something like a Subaru Outback by squashing it on the vertical axis unless you stretch it in another dimension or find somewhere else to find space. Maybe you might be able to eek out a slightly better angle on the hatch or something but it ain't gonna be much. Fuel economy regulations make cars with thicc asses like the big sedans and station wagons of yesterday nonsensical.

The snark is not needless. It is tautologically impossible for the overwhelming majority of people do be "doing it wrong" on a matter that is in large part a subjective one of preference. If someone wants to assert that then I will talk down to them.

People buy these small SUVs left and right because they're seemingly the best option when it comes to well rounded boring A to B vehicles.

Like absolutely, unless you consider 1.4L petrol engine large for something with over 170KW (over 220hp). Such kind of offerings are quite common at the East side of the pond.

I have no doubt that some people behave as you describe, but I think some of that is driven from a rational position of not wanting to buy a car that is incapable of anything more than their normal daily driving. If you need to accelerate quickly to merge safely into traffic, bringing only 75 [or 71] peak horsepower to the table isn't a comfortable position to be in.

The sub 100 power doesn't mean much if the engine has a turbine, e.g. TSI of volkswagen

https://en.wikipedia.org/wiki/Exeed_Yaoguang

Toyota Yaris - HSD - 1.5L 4cyl Renault Clio - E-Tech - 1.6L Hyundai Kona (SUV) - 1.6L Honda Jazz - 1.5L Peugeot 208 - 1.2L Peugeot 3008 (SUV) - 1.6L Peugeot 5008 (Family SUV) - 2L And the list goes on. Even BMW with it's xDrive puts out 1.5L engines.

Huge engines are only common in two places: sports cars (and even then, only a specific category like AMGs and friends, because even a Porsche 992 only has a 3L engine) and the US.

1.5L is an incredibly small engine, especially when previous versions required much larger. The Renault Scénic IV is a 1.5 ton brick that is happily running on a 1.2L engine. The Scénic II's most sold motorization was a 2L engine.

edit: oh it was mine heh, my first car was a 1979 ford with a 460 ( 7.5L v8 ). It was a hand me down from my grandfather, he said if i could get it running i could have it.

They go test-drive cars, probably glance at performance specifications and/or read/watch a test drive review of the cars. They can look at the 0-60mph/0-100 kph times and get a feel for "this car will be able to get out of its own way" vs "this car will be a rolling roadblock".

So "actually understand"? Maybe not, but "understand enough to guide their purchasing decision?" and therefore enough for the actual automobile product teams to design to accommodate? I think they do.

In 2010 with the Chevrolet Volt.

I hired one on holiday and it worked fine. Maybe I'm getting old but I see less point in getting something that does 0-60 in 4 sec when most traffic goes from 0-40 in about two minutes and doesn't get much faster. It still has a top speed over 100mph.

So what is the well to wheel efficiency of this vs. pure electric? There are fuel transportation losses in one, and transmission line losses in the other. In many cities electricity is quite a bit more expensive than gas so hybrids are a better deal financially.

Those are super rare though.

Seriously though, hybrids seem like a bad compromise to just getting an EV. Hybrids have an electric drive train with an ICE drive train, and somehow that double complexity will be worth it? In the long run, EVs are winning on cost alone (especially in China where making cheap EVs is a thing).

There are a handful but most hybrids are either parallel or series-parallel. I assume because the power range is so low that the conversion losses are way too noticeable compared to a mechanical drivetrain.

Honda even recently announced that they're scaling back on electric to focus on hybrids:

https://www.reuters.com/business/autos-transportation/japans...

[1] https://www.bloomberg.com/news/articles/2023-12-19/hybrid-ca...

The Toyota Prius powerchain has two motor generators, and can take part of the ICE power from one and transfer it electrically to the other, remapping the engine RPM into more efficient power bands at the same time. It has a mode that can do this even when no power is being used from the battery.

It’s kind of a best of both worlds. They can avoid the extra weight of a full series hybrid, because they don’t need a motor generator pair that handles the full engine power.

Actually, power bands remapping is essential for the Prius to operate.

There is no clutch, there is no neutral gear, there is no torque converter. The ICE is always connected directly to the wheels with a fixed gear ratio on a planetary gear set. (Which improves transmission efficiency over a automatic/CVT gearbox, and actually reduces maintenance costs)

One of the motor-generators is on the 3rd input of the planetary gear. For the ICE to idle (during warm up, or when you have the heater on), the motor-generator much be spinning backwards at the exact same speed so that the wheels stay stationary.

Power band remapping can also be used for reversing when the battery is empty.

https://www.youtube.com/watch?v=QLUIExAnNcE has more info.

Close: they have the highest efficiency at about 90% of maximum torque for most of the RPM range. So if you want double the power, you want to be able to double the RPM; and if you want half the power, you want to be able to drop the RPMs in half. To pull this off, you either need a very quick shifting gearbox or some sort of CVT.

This is also why automatic transmissions, despite being ~80% efficient versus ~95% manual transmissions, are not much worse on mileage. Because they can quickly switch between low RPM and higher RPM (first by torque converter lockup, second by switching gears).

i believe there is also a chinese company which is making such a car, their cars have nearly 1000 miles range.

edit: Thanks for the correction. They do indeed use resistors and just dump the energy as heat. Unfortunate.

Hopefully this will change as supercaps continue to improve. Maxwell tech's modules are already used in light rail, and looks like some work towards smaller locomotives in Switzerland here:

https://www.osti.gov/etdeweb/servlets/purl/20823697

Dynamic brake

Which is why I'm surprised electric cars with range extenders aren't a bigger thing:

* https://en.wikipedia.org/wiki/Range_extender

Have the powertrain be all-electric, and have a battery pack, but for those with range anxiety have a small generator as an option that would go in the frunk (front truck). A (proverbial) small Honda EU2200i would be less maintenance than a traditional engine.

The #1 reason for (european) companies not buying full EV vans is range, they need to drive a LOT during the day.

REX would solve that with minimal emissions. And depending on the battery size, they could drive on full EV in city centres and only allow the REX to charge the battery during longer drives.

The BMW i3 REX is a fantastic car, if you can find one, buy it.

I think a Diesel indirect injection REX would be awesome. It could burn vegetable oil, which is more viscous, but indirect injection doesn't need to atomize the fuel as much.

Could you expand on this? What was the actual problem? For example, did the range extender start and run? Did it put any energy into the battery at all?

I don't know what to call this.

"Legislated fragility"

And yet that's what an ICE car is.

So a range extender (RX) should be no worse than ICE: in fact a little less complex because you don't have a gear train and transmission.

> The LEVC TX is powered by a full-electric hybrid drivetrain. It drives in full-electric mode all the time, but is recharged by an 81-horsepower (60 kW; 82 PS) Volvo-sourced 1.5-litre turbocharged three-cylinder petrol engine.

Assume the car gets 4 miles per kWh delivered and the charging cycle is 90% efficient (measured from generator output). The 2.2kW generator can add 8 miles/hour of generator runtime (2.2 kW * 0.9 * 4 miles/kWh).

For range anxiety of the form "we're driving to a destination pretty far away and I'm not sure we can get there", that's not very helpful. For range anxiety of "I'm driving to a destination that's over half my range and then going to spend a full day [or overnight] there, but I'm not sure there will be working chargers available there", charging 8 mph times 8-10 hours is very helpful.

Worrying about being stuck in the boondocks without a charger is addressed by an 8 mph on-board charger, but I think that's the less common form of range anxiety.

The Chevy Volt range extender was 75kW; the i3's was 26.6kW. 2.2kW is literally an order of magnitude too small to replace those.

Also, something I didn’t mention in my post; at full power they’ll suck their tank dry in a little over 3 hours. You’ll get about 20 miles of range (using your assumptions above) from one. Tbf you can also parallel two of them, or buy a slightly larger model (EU3200i), but either way, it’s still not going to be anything other than an emergency backup where you have a lot of time to kill.

Re: maintenance, small engines typically are pretty needy. That one wants an oil change, spark plug gap adjustment, and spark arrestor cleaning every 100 hours of use. The latter two are only usage-based, but the oil is time-based as well (6 months) since it oxidizes, and suffers from fuel dilution. Then there’s the fuel: god help you if you put ethanol gas into a small engine and let it sit for any period of time. It’s often difficult to find E0 fuel, and while there are external fuel tanks for generators that can hold quite a bit, they also tend to vent vapor in the heat (as does any tank, including a car’s), which is unpleasant when it’s in your frunk.

Finally, engines of all kinds really don’t like being left sitting for months on end unless prepared to do so. Generally you want to run them monthly, getting them up to operating temperature, putting a load on them for a bit to fully exercise all components.

I say all this because I have an EU2200i and dearly love it, but am also painfully aware of its limitations and needs. I got it when I lived in Texas because the power outages were getting to be absurd, and my house wasn’t plumbed for natural gas, so a whole-house was out of the question. The 2200i was plenty to power two fridges, a deep freezer, TV, fans, and my server rack. I got really good at quickly running extension cords (which is a whole other discussion on ensuring proper amperage ratings and calculating voltage drop, something most people ignore).

proverbial

As dboreham says in the sibling comment, the range anxiety morphs into charger-availability anxiety. Even if I know a charger physically exists at my destination, if it's 45% or more of the range away, I still need to worry that it will be working, that my access will work, that it won't be occupied or blocked, etc.

In nearly 40 years of driving, I almost never researched gasoline availability (through the Nevada desert and in Central America, I did).

In a little over a decade of BEV driving, I've done a lot of EVSE (charger) researching.

Today, if I run out of petrol|gasoline somewhere, even if I'm in the middle of nowhere and don't have a gas can, I can still recover from that situation within an hour or so (hitch a ride to the next gas station, buy gas can, fill with gas, hitch back to my vehicle). With an EV the density of fueling/charging locations is orders of magnitude lower than for gas, and if I end up discharged I'm looking at finding a flat bed truck, or perhaps a mobile high power generator.

Disclosure: I own both kinds of vehicles.

I've had my BEV for about 5 1/2 years. My first road trip (Portland -> Santa Clara, ~560 miles each way), I planned it out ahead of time with ABRP. These days, I'll just let the nav figure it out.

I have been totally unconcerned about it since.

You’d need to tow around a 7.2kW 240V for 30A at 240V (more likely a 14.4kW generator for 240V 60A).

Using the small Honda inverter generator (which is amazing for plenty of stuff!) is akin to covering your car in solar panels to get range extension, the math just doesn’t work out.

The "gas pedal" becomes a "I want to go faster/slower" pedal, its position has zero impact on the RPM.

As an anecdote: A security company I know only buys Toyota Hybrids for their guards just because of that. They have a habit of driving cars like they stole them and normal ICE cars break down from that kind of abuse. Hybrids won't let you abuse them, they pick the RPM and you deal with it.

(They also swap the passenger seat for a plastic box because the guards threw heavy crap like safety boxes on it, wearing down the seat in months)

I'm also surprised for the first few minutes when I drive it how little "engine braking" it has (my habit is from riding a big motorbike).

With other hybrids: depends on the generator they have installed, but it matches the consumption in amps by the engine in order to "go" if it is not directly coupled with the transmission, or they just downshift to accelerate with help of the electric engine.

I am assuming a lot here: Toyotas (specially RAV4) mount CVTs among others, assuming pure electric generator by the ICE or coupled to it... So it depends a lot on specific configuration.

Both will rev on neutral, but when the gear selector is on Drive there is no link between the pedal and RPM.

I know it's not exactly the same, but I was a teenager and curious, and you can rev them and shift into drive with some heel-toe finesse. Not sure if this works on the newer ones, this one was an early 2010s model.

Trees, multiple motorcycles, final destination esque road debris, an accident that should have totalled it if not for an insurance mistake, leading to repairs worth more than the car. Three teenage drivers and two adult drivers with heavy feet. Not to mention many many hardware store runs hauling various sacks of yard materials, baby trees, lumber, etc.

My favorite times were rallying on compacted un-plowed snow. The thin tires and light weight meant it absolutely shredded.

It's my opinion that the Toyota Prius is one of the greatest vehicles ever built and they should be respected and feared.

Losing muscle memory of pressing the brake pedal. Makes sense, actually.

China has banned "one pedal driving" as a default.

Regardless, your point stands. People that have gotten used to not directly using brakes to indicate you are slowing down is a dangerous thing with how reliant we are on the standard indications that you are slowing. All the more so if you need to rapidly lose a ton of speed, where even regenerative brakes often fall back to friction.

Most, if not all, EVs will light up the brake lights when you're slowing via regen braking as long as the deceleration rate is above a certain threshold. I know my Tesla does.

Emergency brake systems probably help a lot with this problem, of course. Still seems wise to follow some of the older practices that we used to drill into people.

There are some really good videos out there going over how newer CVTs work. Looks like some people are working on ones that are teeth driven, to reduce the loss from being free belt driven. Borderline magical stuff, all told. (Obviously, not magic magic. But very very impressive designs.)

From a mechanical engineering standpoint, the Subaru CVT uses a fairly conventional lock-up torque converter at the input, but that gets locked as you pass something like 15-20 mph (once the lowest gear ratio is satisfactory w/o the torque converter function) and beyond that all shifting of the CVT is done w/ the torque converter locked. In addition, the clamping force of the sheaves is adjusted per the torque load of the transmission to minimize the frictional losses.

Anyway I'm curious about data comparing efficiency of conventional and CVT automatics.

The videos online that look at various CVT systems is truly an amazing resource that I regret not having when I was younger. :D

This would be similar to hitting the optimal torque point. The idea there would be that you can get out of the acceleration phase faster, so that you can transition to a more efficient gear to maintain the speed for longer.

The wikipedia looks to cover this well. One of the cites is specific on the efficiency of the CVT. I think I overstated how much higher the loss is, so maybe that is confusing things? I thought it was 10-20, but the cite on the page shows it solidly around 10.

Interestingly, my car gets better gas mileage around the 40ish speeds than I do at full highway speeds. That somewhat surprises me. It is very dependent on not having a heavy foot, of course.

The main reason why city mileage is usually lower is because of all the stopping.

For EVs, the drivetrain efficiency is so high that it's variability with operating point doesn't affect this calculation much, and so the most efficient speed of an EV is around the speed at which the fixed losses equal the aero ones. This will vary greatly with environmental conditions since AC or heating load can be large in hot or cold conditions but at the right temperature will go to near zero.

In ICE cars, the drivetrain efficiency is much lower and so the drivetrain efficiencies are a much more significant part of the optimization problem, but the basic physics of the aerodynamics are the same.

The model I used to use in my head is that for an ICE, the most efficient operating point is probably around the lowest speed the car can operate in the highest gear, so maybe around 40 mph / 60 km/h? Obviously a rough heuristic though.

They use a series-parallel hybrid transmission which is sometimes called eCVT, but works completely different from a classic CVT. There are no pullies, belts, chains, none of that. What they do have is a couple of motor-generators and a differential to link the system up with the engine and the drive shaft. No friction losses like CTVs have.

See https://prius.ecrostech.com/original/PriusFrames.htm, or look up "Hybrid Synergy Drive" on Wikipedia or Youtube or your favorite search engine.

Is fascinating to watch these things work.

A direct mechanical connection is more efficient at highway cruise speeds than a mechanical->electric->mechanical conversion.

The main win a gasoline hybrid has is in running the Atkinson cycle gaining efficiency while losing torque which the electric motor makes up. This brings the gasoline engine up into diesel efficiency territory.

This is also why you don't really diesel hybrids, the engine is already very efficient but it is more expensive and heavier and hybrid adds more expense and weight.

Though H/K have recently introduced a new hybrid system with a CVT, so maybe 2026 or 27 model years will be different.

Since I'm only making one comment, I also want to say hybrid cars are better than ICE because there are fewer belt-driven accessories. Aircon in particular on an electric motor is a big improvement. Without the idling engine producing heat, hybrids are much nicer in hot stop-and-go conditions!

Also my Prius made it its whole life (200k miles and ~20 years) without ever changing the brake pads... amazing!

Toyota and Lexus, obviously, use eCVT in their cars.

Honda is also in eCVT camp for most of their models but for example new CR-V has weird setup. It acts as an BEV until ~80-100kmh and then shifts completely to ICE with a single gear. While in EV mode the engine is constantly charging batteries.

Then you have KIA and Hyundai with their dual clutch setup in all HEV and PHEV range.

I find it a pity that Lexus uses CVTs as I would probably sell my BMW 330e and get a Lexus.

> The gas engine has maximum efficiency at about 80% throttle.

ICE efficiency varies in multiple dimensions based on load and RPM, and in a series hybrid, you have some ability to dynamically influence these... throttle would be one of those inputs.

However in practice the vast majority of hybrids do not use this approach and have motors that vary RPM with road speed (depending of gearing of course).

The common case of maintaining ideal RPM is the CVT, which most folks dislike, so much so that some models have a switch to pick how many fake gears you have to break up the boring drone of a constant RPM engine.

BTW, the chevy bolt was advertised as a serial hybrid, right up to the day it shipped.

I believe the most common serial hybrid today is an EV with a range extender.

I remember buying plans from the Whole Earth News for such a car back around 1980. That was the selling point - keep the ICE running at an optimal point. I've not seen those same plans reproduced online.

Also known as breaking. You could just do that once in a while.

Car producers can and do resolve this, e.g. iirc Audis don't use recuperation for the first breaking of the day. That way you don't have to remember to use the no-recuperation/break cleaning mode or break unnecessarily hard every now and then.

(When I say "the manual", I mean both the manual of my previous car which was a hybrid Toyota Auris, and my current car which is a fully electric Volvo XC40.)

* https://www.dictionary.com/e/brake-vs-break/

The two words are:

* https://en.wikipedia.org/wiki/Homophone

It's 2025 and hybrids have enough software to automate some non-hybrid braking action.

They’re enclosed so they don’t get dirty, the inner face of drum will rust less than discs, fade is not an issue thanks to regen braking, and before they get too hot and fade drums will brake harder than disks (thanks to a higher pad surface area). And they’re enclosed so they also keep the brake dust inside the drum, making it easier to dispose of safely.

Drums are heavier tho.

> They should add some “brake cleaning” mode to temporarily disable regenerative braking.

Some manufacturers do that (iirc tesla calls it burninshing, others will switch regen off completely if you switch to neutral or something).

I've read that Audi and Porsche will use regular brakes once or twice at the start of every drive instead of regen, I assume using electronic control to imitate the current state of regen braking.

But I understand the factory tires are a bit stickier to create a quieter ride which may be throwing more rubber dust into the air. High torque launches don't help either. ;-)

> As of the end of June 2025, there were 2,450,462 plug-in cars, with over 1,585,000 battery-electric cars and nearly 865,000 PHEVs, registered in the UK.

> There are more fully electric cars than there are plug-in hybrids on UK roads and the gap has been widening. In 2021, fully electric cars accounted for 60% of all plug-in cars but with the increase in options, range and popularity of fully electric cars, and by May 2025 this has increased to 65%.

(That stat does exclude non-pluggable-hybrids, but those are kind of pointless stalling of the transition off petrol)

https://www.smmt.co.uk/more-than-a-million-evs-on-uk-roads-a...

We have a selection of smaller popular hatchbacks with MHEV available (ie, the Hyundai i20) that I believe were not released in some markets

The leasing culture for "luxury" cars is quite prevalent here too, and many new cars from popular brands such as Land Rover are at minimum MHEV from new nowadays, in order to get fleet emissions down

Hybrid cars have smaller motors, inverters, and battery packs - and none of those components can absorb 940 horsepower!

A 2nd gen prius battery for example has a max in/out of 30 horsepower.

Some cars it's quite an abrupt change from the regen braking to the hydraulic brakes.

Also is it only pedal braking? Or does it "fake" things out if you use one-pedal driving?

Quote from the actual report:

> As the level of electrification of a vehicle rises, the dependence on regenerative braking also increases, thus lowering PM emissions from brake wear. Based on recent evidence [30], regenerative braking can reduce, in the worst- case scenario (i.e. highest usage of mechanical brakes or equivalently lowest usage of regenerative braking), brake wear emissions by 10-48% for hybrid electric vehicles (HEVs), 66% for plug-in hybrid electric vehicles (PHEVs), and 83% for battery electric vehicles (BEVs

I remember decades ago where they figured out the horsepower of a high-end porsche to go 0-100-0, and if the acceleration horsepower expended was 500hp, the deceleration horsepower absorbed by the brakes was probably 1000 hp.

I wouldn't be surprised if hybrids could only absorb 10 hp, while bigger cars could absorb 50.

One thought - if any of these manufacturers provided "braking resistors" like diesel-hybrid locomotives use, regenerative energy could be electrically turned into heat, instead of mechanically by wearing the brakes.

using resistors would be "green".