Grill block white board
 

Not much data to start with or to end with, but I've seen folks use cardboard and plastic for a grill block project. I used discarded white board material. I've realized that sometimes folks buy a white board and either return it to place of purchase or just throw it out after someone uses a permanent marker instead of a dry erase marker. Since it is white and my Geo Metro is white, I thought I'd experiment with a grill block. I used some tin snips, a hand saw, and a drill to rough cut a piece of white board based upon an original pattern created from plastic. The final outcome is not airtight but took about 10 minutes and bolted right on (or screwed right into place) using existing bumper mounting screws. Just thought I'd share. No mileage data at this point. Haven't been recording any, but just needed to get another vehicle running in the family and thought I'd be the one to drive and work on this 1991 Geo Metro.

Large picture of what may be final draft...
 

Noticed that the other pictures were only about 160 X 160. Tried to make this image larger...

are grill blocks an *areo* thing or a *WAI* thing ?

if Aero then i suggest trim to fit and angle the bottom back a wee bit , to smoothly as possible match the existing angles/slope of the fairing

At any rate during the heat of summer watch your engine/coolant temps closely .
even 5 more miles a gallon is not worth melting your engine down

good luck

Aero - yes, but mostly to speed up engine warm-up time. And in some cases (like extremely efficient hypermiling) to allow the engine to stay at a decent temperature.

Making the block more flush wouldn't hurt, but you might also want to leave some room behind it so the fan has a way to draw in fresh air if the temp rises.

Took a quick test drive. Not really sure what I was expecting. Have no data to compare before or after...and of course it was during a local heat emergency. Electric fan came on for the first time since I can remember. Temperature didn't go up much but I kept an eye on it. I read a few threads where folks were polled about the top physical mods they did to increase their MPG.

The way I saw it:
1) Maintain or increase tire pressure
2) Grill block
3) Front below the bumper spoiler

Thought I'd try a those and of course being focused about my driving habits. Drive as if there is an egg between my foot and the gas pedal.

Thanks for the feedback!

*Drive as if there is an egg between my foot and the gas pedal.*

thats what i thought too, but i was dissuaded by some thinking/analysis on this site

consensus seems to be to accelerate *briskly* not to say floor it IE: jack rabbit starts .

then when at most efficient speed in top gear apply your driving techniques..
[minimize braking, time the stop lights , pulse and glide .. whatever]
this permits the engine to operate in acceleration at a more efficient range,

in top gear i *feather foot* the Foot feed [throttle.] i don't know if that's right or not


if the electric fans are running all the time any FE gained by the block *might* be defeated by the electric energy consumed by the fans , or maybe not.
if grill blocks are primary to hasten engine warm up shutters like the big trucks would be better, thermostatically controlled to open at the desired temps,, quite a bit beyond my DIY ability