Front bumper shape

[CigaR007]

Originally Posted by Sentraguy

So riddle me this Batman, if we leave the front un-modified, and boat tail the back, will that still dramatically improve gas mileage?

Yes sir.

[cfg83]

COcyclist -

Originally Posted by COcyclist

...

IMHO if you can get your car to look closest to the Impact concept, the better. So, smooth, gently rounded is best. Post a photo of the finished one?

You mean the EV1, yes? :





CarloSW2

[drmiller100]

that car is interesting how steep the rear window is, and yet somehow they keep the air attached. I wonder if they are using energy from the air coming from the sides to keep it attached to the rear window.

[euromodder]

Originally Posted by drmiller100

that car is interesting how steep the rear window is, and yet somehow they keep the air attached. I wonder if they are using energy from the air coming from the sides to keep it attached to the rear window.

The well-curved and boattailed sides (see plan view) have the effect that they can get away with a steeper rear-angle.

[Patrick]

The EV-1 shape is not optimized. AeroVironment wanted to use a smaller angle on the back glass but they were overridden by GM.

[Gone2]

So I installed a 200sx bumper and used heavy duct tape to close off the openings. I saw dramatic improvements in coast down distance as everyone does. The surprise is when I ran across a 200sx grill, or I should say grill blocker as my year range was just a small gap at the bottom for an opening, installed and filled up my tank before heading home. Normally the gas guage is sitting at Full, not above by the time I got home. Today, the gas guage still sets above Full, not all the way to true full, but still above. I know this is not the best way to judge fuel economy, but it is the only way I have right now. The further shock is on the slow hills that my car was holding the speed going down, today gained speed going down. I am installing the taller tires tomorrow, and will let you know how my overall mileage does.