[GMPG]

Just a place marker with coastdown speeds and "hill coast" speeds which I'll check again after mods and before filling up (1/4 tank now) or packing the car.


Coast down:
42.56 seconds from 60mph to 35mph.
-------
45.24 seconds from 60mph to 35mph with mods
-mods, upper and lower grill block, air dam, hood cowl.

So 2.68 seconds longer to coast down

This is on as level a stretch of road as I can find locally, four timed runs in each direction and I threw out the high and low outliers. It's not science but it's something...

Hill Coast:
Entry marker 55mph
Mid point 62mph
Exit point 55.5mph

Hill coast with mods as above in this post.

Entry marker 55mph
Mid point 63mph
Exit point 57.5

Up 1mph at the mid point and 2mph at the exit. I also was rolling several mph faster when I hit the 35mph sign coming into my town that I normally hit right at 35mph while coasting.

This is a regular coasting spot for me, I usually coast out of gear but I can shut off the engine and coast about 1.5mi down hill, back up and down again to the next stop. The uphill even puts me right at the speed limit for the final downhill leg! (35mph)

Metro: I also used my ultragauge to try and test the real world MPG over the same road at the same speeds etc and could not see a difference as closely as I could measure it. I may or may not hurt or help but either way it isn't much of a difference. If I was keeping the car I'd think about a shallow kam back but rear visibility leaves much to be desired on this car as it.
Rear visibility was actually the main reason I removed the wing. I always hated the look of it but it also made backing up a rear pain because you couldn't really locate the rear of the car. I'm tall and it was an issue, for someone under 5'8" or so it might as well be a panel truck back there!

Next update will be post mods.