No rear window wiper on some new cars - why?

I have noticed that on a number of new model cars there is no windshield wiper. Why? And, what is the driver to do if there is a heavy snow? I find it hard to believe that the heater wires in the window and the car heater system will keep the rear window clear during the kind of heavy snow we sometimes have in SE Pennsylvania.

@vklip

Sedans and coupes have almost never had rear wipers

Vans, SUVs, and station wagons have often had rear wipers. But there have been some exceptions

Many hatchbacks have rear wipers. But some don’t

A thought . . . there have probably been studies which show that most people never use the rear wiper

My brother, for example, has a rear wiper on his SUV, and I know with 100% certainty that neither he nor his wife ever use it

If the rear window is angled, as on a sedan, the airflow works to keep the rear window clear of falling rain and snow enough to see in almost all cases. It’s true that in very heavy snow if you’re crawling along the highway some snow might build up, but that’s pretty rare.

If the rear window is vertical at the very back of the car, as on an SUV, then the airflow is different. On those vehicles, the falling precipitation plus the spray from the wheels tends to end up being sucked onto the entire back of the car, so you need the wiper (and a washer) to keep the window clear enough to use.

This has been true for a long time, so there’s nothing different about late-model cars here.

By the way, you honestly don’t have heavy snow there in general. I assume you’ve never traveled around Watertown, New York, in winter.

Well, one thing the rear defroster grid is not for is removing ice and snow. It’s a defogger only; anything else it happens to do incidentally is just an extra.

In Minnesota I’ve never had a problem without a rear wiper. The wire defroster keeps windows clear. I’ve noticed many have rust spots developing under the wiper also I expect from using the washer as it drips down on the paint. One day I saw a lady driving down the highway mile after mile with her wiper going, except it had dropped down so it was wiping the tailgate mile after mile. Drives you nuts not unlike the guy that leaves his signal light on.

The first generation Mercedes-Benz ML class SUVs . . . late 1990s through mid 2000s, had a rear wiper. And the rear washer jet would invariably break

it would break in such a way, that it couldn’t shoot washer fluid at the windshield, but only straight back

In the shop, if we were working on such a vehicle, and knew the rear washer was broken in such a way . . . we’d wait until somebody walked past and squirt them

Of course, if that guy had a lousy sense of humour, we wouldn’t do it again. But if they were the average guy, they’d laugh it off, and wait for their chance to give you a dose of your own medicine . . .

:innocent:

@ok4450: Yeah, it’s more of an “anti-ice” device than a de-icer: it’ll keep ice off a clear window, but won’t do much to melt ice already there. I’m surprised OP sees a lack of rear window wipers as a “new” phenomenon: can’t say I’ve seen many Chevy Bel-Airs or VW Beetles with rear wipers…

I don’t think it would be a dealbreaker, if I was shopping for a new vehicle, and it didn’t have a rear wiper, if the car was right for me in every other way

Even if it was an SUV, I don’t think it would be a dealbreaker

The first cars I remember seeing that had rear wipers were the 1948 fastback Pontiacs. I had a 1947 Pontiac Streamliner fastback and I can tell you that a rear wiper on the car would have been as useless as a screen door on a submarine. The rear window on these cars was even useless–it pointed up to the sky and was more like a skylight. The first car I owned that had a rear wiper was a 1975 AMC Pacer. It did help a bit. In really icy weather I could turn on the rear defroster and as the started to melt,I would turn on the rear wiper. Our Toyota 4Runner has a rear wiper and all four minivans I have owned have rear wipers. Combined with a rear washer I find the rear wiper useful. I really don’t think the rear wiper is needed on a conventional car.

I’ve never owned a car with a rear wiper. While I could see it being convenient if you park for a few minutes and just want to clear off light snow, with every car I’ve ever owned, as long as the car’s cabin is warmed up, snow will not accumulate on the rear window—it melts just as fast as it touches, even with the rear defroster off.

I have owned a few cars with rear wipers but none of them ever worked very well. They worked like they were designed as an afterthought…a poorly designed afterthought.

It would be nice if the OP returned to explain why he even made the question and what type vehicles he is referring too.

I’ve never had rear windshield wipers, and I never had a problem, even in snowy Colorado. I’ve never even once wished I had rear window wipers. If I was staying at the ski resort and parked outside and there was a 2 foot snow, before I’d leave I had to wipe the snow off all the windows first with my snow tool from the outside, but that was it. As long as the inside of the car heated up as I drove, along with the air blowing across the windows due to motion, the rear window wouldn’t gather much snow, and what it did gather would get quickly dissipated.

The rear electric grid defrosters work well to keep ice and snow off the rear windows around here. Of course if you have a foot of snow on it you should remove it before you drive. I agree the Southern PA doesn’t get much winter.

I see wipers on all the vehicles that had them before. I don’t understand the question.

I would also hope that if snow is piling up on the rear glass while the car is in motion that the driver will not be so focused on what’s going on behind them that they forget all about what’s up front.

If a car had a rear wiper previously and is now manufactured without one I’d say the bean counters found a new way to improve the profit margin.

The only vehicles I’ve ever owned with rear wipers were the family minivans. Coupes and sedans don’t need them. Airflow over vans as it goes past the rear edges creates a very low pressure area over the rear that draws in crap and deposits it on the rear end. With sedans and vans, the air flows over the glass and carries the crud with it.

Aerodynamics and hydrodynamics is cool stuff. I visited a dam today, and observed an interesting phenomenon. Behind the edge of the dam where the water flowed over were streams of bubbles coming up. Upon further observation, I began to understand that there were leaks where the seams were in the dam, but rather than the water leaking down through the passages, the laminar flow of the water, apparently low pressure at the barrier layer, was drawing air up through the passages from the high pressure turbulent air behind the waterfall. It was like observing a leak working backwards. At least that’s my theory. Bernoulli would have been intrigued.

Salt accumulates on the back windows of minivans in snowy areas. When you turn on the rear washer and wiper it sends a stream of salty liquid down the same area of the liftgate every time and that is where the rust holes appear.

@oldtimer 11: I hadn’t thought of that, but you’re exactly right. I see a lot of cars that have rear wipers with rusty streaks in the same spot.

I think they are an expensive nuisance,most people dont even look very far bacK
,Why doesnt it snow in SE PA?(plenty of snow in WVA, in the Alleghanies downwind from the lakes,as a matter of fact the western slopes,dry the air out before it reaches were I live and we generally dont get snow from that direction(our heavy snows(rare-are Noreasters and Gulf moisture pumps)