I had my lower grille totally open this summer and now that it's getting cooler and the A/C isn't as needed I have blocked 60% of the lower grille. hopefully my milage will get better with this. this summer I ran a consistent 29mpg not remarkable but I had to use the air con almost every day.
I'm new to this gig, and I have not figured out if grill blocking is solely for aerodynamic benefit, or if it is somehow better to have a hotter engine compartment. I'll be blocking up the stretchscort this weekend, now that it's cold and rainy in Maryland....
Thanks Philip- Another thing - do you get your intake air from the engine compartment or outside? This is another part of grill blocking that I don't understand. Is hot intake air better than cold? I've read about people boring 2" holes in their filter housings to allow warm air into the intake.
I have a cutom intake that gets air from over the exhaust manifold. Wehter hot air is better depends on the type of fuel injection you have. I would suggest experimenting to see if hot air will work with your system