I have a 98 suburban with the 5.7 liter engine. Driving a careful 55 mph
gives me 21-22 mpg on the level in Iowa, On hills and winding roads drops
down to 19-21 mpg. Driving freeway speeds with the air running and keeping
up with traffic going 75 mph drops me down to 17-19 mpg.
I am interested in knowing if I can do anything under the hood to improve
mileage, Ive seen electric fans, synthetic oils for the gear boxes yet I do
not want to venture into this area because I suspect I may be wasting money
by getting 0.00001 mpg improvements, but then, I dont really know.
Also, can I do anything with aerodynamics to reduce drag....fold back
mirrors (maybe this is extreme) for example, airflow deflectors..etc???
How about the daylight running lights, anyone know what shutting these down