So my 96 3.8 has been getting awful gas mileage. I drive to school(about 40 miles one way) its mostly highway/freeway 65mph, 78mph. even before i started going to school my car will get 20mpg freeway or city doesnt matter. ive gotten 24mpg once when i used some fuel injector cleaner. only thing that i can think of that is holding it back could be that my egr is nonfuctioning/blocked off. She hads 200,xxxmiles but runs like a champ no coolant leaks no oil leaks great oil pressure. Im just curious to see if anyone has any ideas or insight to help me get to the 25-28mpg range without having to put injector cleaner in every tank<---sorry just thought this is awesome

 

Good luck trying to get that kind of mileage. Make sure the spark plugs are in good shape, tires properly inflated, and use cruise control. The EGR whether working or not, won't make much difference in fuel economy at highway speed.

 

You can do some other things to improve the efficiency of your engine and thereby gas mileage, assuming no lead foot.

Look into a cat-back, high flow cat, CAI, headers... But you may have some other maintenance that needs to be done also, such as fuel filter, plugs/wires, cleaning the butterfly valve varnish with some cleaner spray. Also remove any unnecessary weight from your car -- don't leave junk in the trunk.

 

i have a 1993 camaro with a 1997 lt4 383 in it i was curious what kind of gas mileage it would be getting on highway and city.