[Purtill]

Has anyone had a problem with the rear glass pitting like a windshield ? Mine has
about 10 pit marks in it . I only have 1000 km on it and a rear spoiler . Most of the
pitting is near the top of the glass . I hope the spoiler is not causing it . The dealership
is checking with the area rep and I'm still waiting .
PS I'm still waiting for a locking gas cap in Canada too .

 

[yelapa]

Hi Purtill,

I do not ask this to challenge you, but why do you have a spoiler? The function of a spoiler is to provide enough downforce to overcome a loose (oversteer) condition at high speeds. The kinds of spoilers that we see on street vehicles are not large enough to achieve this effeect because they are way too small. So they are mainly for appearance. The most ridiculous exmaple of this are idiotic spoilers we see on Nissan's Infinity (sp?) line. Anyway, these little spoilers DO provide a degree of vacuum behind the vehicle at highway speeds, and the pitting near the top of the glass is consistent with where there is the most vacuum. Also, since the E is peretty much a brick from an aerodynamic standpoint, the effect is likely enhanced.

Meanwhile, there have long been suspicions that Honda glass is "soft." I do not know the extent to which these suspicions have been susbstantiated. It will be interesting to see what Honda says. I have a feeling that they will do anything and everything they can to sandbag you.

Long term, you might want to consider removing the spoiler because the best case effect is a perpetually dirty rear window and the worst may be more of something like what you are experiencing right now. This is just my opinion. I could be wrong. However if Honda says there is no problem with the spoiler, then asking them EXACTLY what effect the spoiler has on airflow might be an interesting (and arresting) question to pursue.

yelapa

 

[burnt-O]

No pitting here. No spoiler, though.

 

[reedpc]

[quote:1f02b5cc7e="yelapa"]I do not ask this to challenge you, but why do you have a spoiler? The function of a spoiler is to provide enough downforce to overcome a loose (oversteer) condition at high speeds. The kinds of spoilers that we see on street vehicles are not large enough to achieve this effeect because they are way too small. So they are mainly for appearance. [/quote:1f02b5cc7e]

You're right, many cars use it for appearnce, but don't underestimate the amount of downforce a spoiler generates. Even if it only produces 75-100 pounds at 65 mph, that's enough to significantly change the handling. Since many cars have the profile of wings, the rear end tends to lift up and the spoiler will really help.

On a vehicle with a boxy rear end, like the E (and most minivans), when you're travelling at speed, there's a partial vacuum behind the car, since the air flowing off the roof doesn't drop down right away. Instead, it drops down a few feet behind the back edge of the car, where it then gets pulled towards the rear of the car, sweeping up dirt and (in rain) the rooster-tail plumes from the rear tires. If you put the car in a wind tunnel, you'd see it as a swirling vortex sitting behind the car, with the bottom of the vortex sweeping towards the rear hatch. (Looking at the car from the driver's side, this vortex will be spinning clockwise.) This is why the rear of most minivans get so dirty.

The spoiler changes the airflow, moving the swirling vortex back further behind the car, thus keeping the rear cleaner.