can anyone rank the following areas which affect the mileage u get per gallon:
air filter
fuel filter
oil filter
engine oil
overinflated/underinflated tires

thanks

 

Tires and air filter...fuel filter, oil filter, and engine oil won't make a significant difference. I've used 10w-30 and 5w-30 with no significant difference in mileage.

Besides your car's state of tune, your driving style plays the biggest part in fuel efficiency. Smoothness is your friend.

 

im getting horrible mileage in my civic. its nearly 30K and i havent changed the air filter. gonna get me a new one today and see what happens.

 

30K without changing the air filter?!!!!!!!! That could be the problem. Let us know how it turns out.

 

use what the manufacturer recommends on all those parts (honda parts) to get the best mileage...

 

i bought one by purolator for 12 bucks. drove 180 miles on highway today and used approxiamtely 6 gallons of gas. i dont know if it is a sign of improvement because its all highway miles. i usually get horrible mileage from local stop-and-go traffic.