I always wondered how this oil-change scam still continues in the US. Modern cars with synthetic oils don't need an oil change every 3-4 months or 3000 miles.

I always changed the oil according to the (European or Japanese) manufacturer's schedule (once a year / every 10-15000km) and had no issues with the cars (even >10 years old cars).

It's interesting you say that... Synthetic oils don't necessarily last longer than mineral oils. The oil itself isn't the problem - its the detergents, friction modifiers and things that break down through heat cycles and over time. As a rule with my vehicles, they get new semi-synth every 7,000kms. When I had my last car (Direct injection petrol turbo), I changed it every 5,000. And that oil was cooked each time.

Having pulled the tops off more engines than I could count, you can immediately tell an engine that gets regular oil flushes compared to one thats run on longer intervals. Sure, the engine might last your whole ownership without having a serious issue... But inside it'll probably tell a different story.

Modern cars don't need it that often, period. Conventional or synthetic.

Parts stores still push the 3k miles/3 months (or did until very recently). Dealers and manufacturers don't, and haven't for at least 10 years.

Modern Diesels in the US have a 15,000 mile interval for oil changes.. but they still put a sticker in your window at both dealerships and oil change locations to come back in 3-5,000 miles.

My 'free oil changes under warranty' deal when I bought my truck required me to come in every 5,000 miles. Their computer system was setup for cars, and they had no way to change it..

My Subaru Forester gets an effective oil change every 2500 miles. It burns a quart of synthetic in that time. Too little to get the recall work done (faulty rings). But at least the car gets a gradual oil change over the year!

Is there a difference though? If you see my other reply to the parent, I posted the US oil change schedule for a european car. It seems to be in line with what I experience in europe .

Is it a difference between european and US made cars?

I know nothing on the matter, but it seems to me that it's a cultural difference. Americans are just more used to changing the oil often, so oil companies can sell them more oil even if they don't need it.

Found this http://www.autoblog.com/2009/02/24/oil-change-intervals/

"For years the accepted oil change interval (as per carmakers) had been every 3 months or 3000 miles, whichever comes first. And why was that? It was because oils of yesterday broke down when left in the crankcase environment for longer than the prescribed interval. The combination of heat, friction, and the oil oxidizing over time resulted in an unholy clothing of the engine's internal parts called sludge."

That's an absolutely insane number, and I have never heard of that (I have had cars for 20 years that always were 10k to 15k km intervals, and simply done on a yearly or 18 months service).

I have a tractor from 1939. The owners manual states that modern oils are much better than old oils and as a result practices of years past do not apply. (I don't recall the exact wording) If you ask collectors today there is a big debate on if it is safe to use modern detergent oils in those old tractors.

It's a difference in the oil used.

The standards for oil are tightly regulated in the EU.

The manufacturers are pretty picky with what oils they recommend for their cars too. I mean if I need a "fully synthetic 10W-30" for my car for example (from the manual) - and the brands are all global megacorps (Shell, Havoline, Mobil, Castrol etc). So with the tight spec and global brands surely I must be getting the same thing in the bottle here as one gets in the US?

Depends. VW has their own 'standards': 502.00, etc. Subaru theirs, and so on.

But many brands meet that spec. It's really only white label conventional bottles that don't.

Most people don't use synthetic oil.

In my case, it's cheaper to use non-synthetic oil and change it quarterly, which generally aligns with other maintenance activity. (Tire rotation, filters, lights, etc)

Here in Europe engine oil is typically always multi-grade, and often fully synthetic. I believe this is because standards are stricter here (although I can't find anything confirming this), and synthetic oil often leads to engines lasting longer and lower emissions.

This is why manufacturers have different recommendations for Europe. The formula of the oil is completely different to the US, so it can stay in the engine a lot longer.

> synthetic oil often leads to engines lasting longer

This is true in theory, but for most people the rest of the car will fall apart before the engine dies. All the rubber and plastic is degraded by air and sunlight which has little to do with any use patterns. (there are of course uses that put more wear on them as well)

A good portion of the cars are junked with so little use that they would have made it that far without any oil changes at all. Of course the oil would be like syrup, and the engine would show other signs of the abuse, but it would still be running well enough to make that last trip before the car is destroyed for other reasons.

You must have missed that he drives 2000 not 20000km per year. He says he changes oil around every year, so every 2000km (1200 miles).

If he changed every 6 months, he'd be changing every 1000km. That's insane! I don't even refuel every 1000km!

Example oil change schedule for a modern car (Taken from Audi Q7 '09 service manual): 8.000km, 25.000km, 40.000km, 55.000km...

So ~15.000km between changes - or 7.5 years if you drive 2.000km per year. Now - obviously you wouldn't go 7 years without an oil and filter change but you should be completely fine changing every 1-2 years on a car that is driven so little (It's the aging of the oil that's the problem, not the distance driven)

Refuel every 1000km... I envy you. Could you share some details, as it made me curious ?

Don't know the specifics of the Audi Q7 of the OP, but my Mercedes A 180 CDI 2012 model (Diesel engine) averages 53 mpg (4.4 l/100Km) for my conmute trip (35 KM total, including ~8 KM of mountain road, with a 300m elevation change). Given that my A180 has a 50 liter (13.21 US gallons) fuel tank according to the manufacturer, that means I could make up to ~1,100 Km with a single tank. In practice I refuel before that, but routinely make ~900 Km between refuels.

Audi A6 diesel (yes very much a dirty VW/Audi diesel-gate diesel, although supposedly "fixed" now). It does 40-45 mpg US (5.5-6L/100km) and the tank is just bottomless (17 gallons/65L or something?)

> I envy you.

Still envy me when I say a full tank is $100? :)

:) I'd spend about $130 or more for the same 1000km.

It's funny how attitudes towards oil change are different in different countries. In Germany, I would never go to the garage just for an oil change. We do an oil change either at the scheduled inspection, or when we're at the garage anyway (for winter tires) and the mechanic says it's time :-) which is about once a year.

My last car was a bit of a beater, and we did the oil change more frequently. Reason was that it had a problem with the transmission (manual, as most cars here), and from time to time there would be little metal shavings in the oil! But apparantly this is less horrible than it sounds, and somewhat normal for old cars. There is even a little magnet in the oil vessel to collect the shavings. After a combination of learning this, and having lived in the states for a couple of years, I insisted on changing the oil more regularly.

Well, I had a German car (diesel engine) for 12 years and changed oil according to the board computer, it came out roughly on average around 32,000 km, i.e. a little bit more than 1 year (sold it with 300,000 km after 12 years).

But the oil of a manual transmission (and as well that of an automatic one) is normally separated from the engine oil, do I read it correctly that you had a car with those in common?

All cars have one or more magnets (for ferrous shavings)it is perfectly normal, but of course they are pretty much ineffective for other metals, and more generally other possible contaminants.

How would changing oil every 2 000 km be a problem? Modern oil should last 10x that long without any problem. I am used to having recommendations for changing oil once a year or every 15k km depending on what comes first. I remember recommendations to change 2 times a year 15-20 years ago because it back then was more normal to have different viscosity in summer and winter

The sticky sludge that GP refers to is for the most part an emulsion of water, produced by combustion and/or from ambient humidity, and oil. If an engine is not run frequently or is used only for short intervals the water isn't driven off by engine heat. Engines that aren't run much must be maintained based on elapsed time, not duration of use, due to factors such as this.

The author's vehicle is a prime sludge candidate, although not as bad as people who go years w/o changes.

Loss of viscosity is a wholly separate form of degradation which along with accumulated Ph changes is responsible for the "every N miles" recommendation.

Spot on

Depends on oil. Many cars still run on semi-synth and those require the 15k/1yr routine, full synth can use longer kms and two years, or every year if you do under 5kkm/year

Changing the oil that frequently probably won't hurt but in a modern car with synthetic oil it's entirely unnecessary.

Almost no car dies because the engine is worn out due to infrequent oil changes, unless the owner just doesn't change the oil at all.

Cars usually get scrapped for some problem that is uneconomical to fix due to the age of the car, long before the engine is worn out.

Anecdotally, my Camry had 3 engines before it was involved in an accident well north of 200,000 miles.

>That poor valvetrain will be full of gummy carbon deposits. RIP whoever buys the car second-hand.

Or actually, the car will be perfectly fine. Nobody changes their cars every 3-4 months in this here parts, and the sky hasn't fallen.

This is one of the most common mesofacts I run across. It's a typical example of something that has changed, but was drilled into people's brains as important a long time ago.

With modern cars once a year is fine with synthetic oil, if not driven enough to hit the mileage threshold.