Also in Mercedes Benz wiper arms: the mono wiper: https://www.youtube.com/watch?v=HKGhKrQmK68

(The weather is too nice in this video, though, so you can't really see how much of the windscreen it manages to clean - however you can certainly see that it manages to trace out more of an ellipse than a circle.)

I had an old 1996 C class with one of these. It worked surprisingly well and never broke.

They're great but if that motor ever goes you will seriously regret it, big$ item and harder to replace than you'd think necessary.

Single wipers leave a huge blindspot of dirty windshield by the top corners where many other wipers wouldn't.

It was coo, but had drawbacks.

Actually, the Mercedes system extends the single wiper towards the corners as it rotates, making it more of a beveled square than semicircle area that is covered.

In fact, it extends farther out than a square form, making it into a bulging square, or something of the like.

We used to have Mercedeses when I was little and I always used to wonder why the inside wiping outline would be round and somewhat M-shaped.

You can kind-of see this in this wonderfully retro polish marketing video: https://youtu.be/XceslAEY2i0?t=69 (watch the lower end of the wiper blade for the outline of the water wiped away).

Great find, thanks :) - couldn't find any good action shots when I was searching, and nothing that showed off that unusual outline (that I remembered from the Mercedes my family had when I was a boy).

Did you ever find out? My guess is that while it looks like there is a fixed axis with variable extension, the axis of rotation itself is also moving from side to side.

Oh, hey, sorry. I did find out, and it's nothing very complicated: The wiper moves out about 10cms during rotation. That distance, applied to a circle with a radius of 10 cm is a large distortion (the inside track), while applied to the larger outside radius just turns it into a round rectangle.

Video of apparently reverse-engineered model: https://www.youtube.com/watch?v=HGO8B86PZDg

That seems so obvious I wonder why it hasn't been done before. I suppose those wipers costs a bit more since it must include some kind of conducts for liquid and multiple hoses(?).

More parts. Fluid needs travel through flexible and/or hinged parts. Longer hose. Cannot spray fluid without wipe (a big deal in cold weather). Fluid in hoses can be blocked (again, ice) whereas parts in engine compartment are kept warmer. No overspray beyond wiped area. No cross-coverage by multiple sprays in case one becomes blocked. Can the tesla sprays be aimed/adjusted by hand?

It's one of the many tesla features i just shake my head about. It sounds cool but there is good reason the other billion cars on the road went with the simple solutions. Water and wipers are cheap. Dont mess with a good thing.

I think the Tesla Model X does this too. One major downside is needing the service center to replace the windshield wipers.

Since the advantage is minimal this overhead makes them generally more annoying than useful.

Very old Volkswagen beetles used air pressure from the spare tyre instead of an electric washer fluid pump. I remember laughing so hard when I discovered that...

I was a teenager. Now that I'm an engineer, it's not so funny; it's an interesting design trade-off.

Because these windshield wipers get clogged all the time and most people at best just use water and windex which doesn't bode well for precision made spray nozzles.

They also tend to leave a mess at any point where you actually need to use the liquid e.g. when you are driving through sand/dirt or mud but then again most people won't drive their CLX through a swamp or a sandstorm.

> most people at best just use water and windex

Who does that? I've never heard of anyone doing that.

Myself and pretty much anyone I know, could be worse seen people use the shitty soap water buckets at gas stations to refill their wiper fluid...

Wiper fluid $2.84 / gal [0]

Windex $2.72 / L [1]

That is, Windex is roughly 4x as expensive.

Granted, you could be diluting the Windex, but it's already mostly water, and it doesn't have any freeze-proof guarantees to begin with, which wiper fluid does. I think you folks are doing this odd thing to entertain yourselves...

[0] https://www.walmart.com/ip/Rain-X-20F-2-In-1-All-Season-Wash...

[1] https://www.walmart.com/ip/Windex-Original-Glass-More-Cleane...

US prices in Europe and in the ME wiper fluid tends to be more expensive, but in all cases it's not the actual cost but the perceived cost (gas station/service center pricing rather than bigbox stores ala walmart) and laziness.

Is Windex worse for the environment than wiper fluid?

It's just a nozzle integrated in the arm, not part of the wiper blade.

Jaguar had that in 2005 at least.

1986 XJ40 introduced it as far as I can tell. (Used to own an XJ40).

Oldsmobile Achieva in 1991 had it too.

I idn't like it - it's nice to let the cleaner soak into the windshield before tearing up the squeegee part of the wiper blade.

I hate that some modern cars automatically do 3 wipes after you spray, exactly for this reason.