Wagons and mini-vans, which have vertical rear windows, almost all have rear windshield wipers. Sedans, which for the most part have sloping rear windows, do not. Why is that? A sloping rear window has more surface area, so you’d think it would be more useful to have a wiper on it, not less.
It’s more difficult to attach a rear wiper when there’s no surface flush with the window. The trunk lid and the roof are both on an angle.
Rear windows on sedans don’t seem to get as dirty as an SUV or Van.
I’d venture a guess that it’s due to the aerodynamics of a particular vehicle. Sedans have a sloped rear window, so while driving air passes over the hood, over the roof, and down the rear window taking some of the rain drops that have settled there with it. As the air flows past the window, over the trunk and down the back of the vehicle, it doesn’t flow naturally away, it actually kicks back up and causes a vortex in the back of the vehicle. Now think about the air doing that against a huge flat surface like the rear on a mini-van or SUV.
We have an SUV and a sedan, and I’ve noticed while driving in the rain, the rain drops on the rear window will sometimes run up the glass on the SUV, but not the sedan.
That’s my 2 cents, but I’m no expert.
- SS
This must be an American affectation, as most cars what would be classed as a “sedan” in the UK do have rear wipers, to the best of my knowledge.
I’m not sure what “sedan” means in the UK, or if they have adopted the US terminology, but at one time, a US sedan was referred to in the UK as a saloon.
Yes, it means “saloon” car in the UK, and no, I’ve not seen any recently with a rear window wiper.
I would assume the boot prevents much spray coming up from the rear of the car and getting on the window. And there isn’t any lip of metal between the top of the window and the roofline as there would be on the bootlid of a hatchback to fit a wiper to.
That would be my guess. Vertical rear windows pick up a lot of road grime, salt spray, tire spray from other vehicles, etc. because of their location.
Slanted windows on the back of a sedan seem to be somewhat protected.
Sure, a sedan’s windshield doesn’t get as much dirt/grime/whatever thrown up on it, but on the other hand, it collects snow like a magnet. Unless I brush off every little bit of snow on my car’s roof (and I do brush it off enough so it doesn’t fly back at the car behind me,) it trickles down onto my rear windshield two seconds after I start moving forward. I mean, what’s the point of brushing off my rear windshield to see if it’s just going to get blocked again? So annoying!!
My 15 year old sedan does have a rear wiper, I don’t use it much, actually, I’ve NEVER used it. I’m not sure if I even remember where the “on” switch is - I’ll have to look. The wiper is mounted directly on the window glass, which leads me to pray that it never gets damaged, because I don’t know where I’m going to find a replacement as the car was only produced in limited numbers and has long since been discontinued.
That’s what the rear defrost is for.
My friend at work who parks next to me has a Volkswagon with a sloping hatchback, and compared to his car, my rear window is super-clean. The rain blows off, and dirt doesn’t stick, whereas his is always super-grimy ever since he managed to break the wiper off.
Out of curiosity, what do you drive?
The Nissan Primera saloon / sedan had a rear window wiper up until 2001: I’m not sure about the 2002 onwards model. The line of the rear window was continued just under the lid of the boot, providing a mounting point for the wiper IIRC. I found it hard to find a picture on the net, but here’s an example of a used one for sale: hopefully the link will remain active for a while.
http://www.carzone.ie/usedcars/index.cfm?fuseaction=car&carID=860691
It definitely has to do with the trunk preventing road grime from splashing up back there, and not the angle of the window. As evidence, I point to the Honda CRX, which has a very shallow slope and still came with a rear wiper (on most models) because there’s no “trunk” to speak of. Of course, some sedans with short trunks still have that problem, but it’s not as bad as hatches/wagons/SUVs.
there are a couple of exceptions. The Mitsubishi Lancer in Evolution trim does have one
I believe it was some Japanese vehicle regulation quirk of the early 90s that made them mandatory, as Japanese market cars from that era seem to all have them.