my car has been stock for a while until i put in a custom intake..just a HKS type filter with adapter..and replaced my steelies with SE rims..well ever since then my mileage has been horrible..i used to fill up my gas every 1.5/2 weeks now it's every week...ne suggestion with what the problem is. i don't really drive too harsh so i don't think it's that and i know intake doesn't kill gas that bad right?

 

What constitues horrible? How many miles are you getting?

 

you could possibly have a bad upstream O2 sensor, clogged fuel filter, any number of things...either that or the SE wheels weigh a LOT more

 

is your new intake leaking at all. Check for vacume leaks. Fuel mite be losing 02 casue leaks causing it to run richer than normal. Did you by a new adapter or made your own???

 

i bought the adapter but it was mad for the 4th gen max..i get around like 15mpg?? for a full tank i go about 250miles...no it's not leaking..

 

what is considered good gas milage for these cars? With my max it has ranged from 22 to 29 mpg. 22 was when i was doing 110 on te freeway and a lot of city driving and the 29mpg was for 400 miles at 80mph.

 

Good gas mileage for 4th gen is 24 mpg. IIRC this is what the manufacturer rating is. When I had dead/dying 02 sensors I was only getting barely 20mpg. After I swapped my upstream sensor I'm getting a solid 24 mpg mix local/highway, pretty much no matter how I drive. This is with all the regular bolt ons (intake, y, exhaust) before and after. These results come from tank milage/gallons filled at the pump.

 

Is 24 freeway driving. I have mostly freeway driving and a little city driving and a barely get 20mpg

 

What pressure do you have your tires at currently since the new wheels? Lower pressure could affect your MPG.

 

I recently got 22MPG with 75% highway and granny style driving (not revving over 2500). I recently replaced plugs and fuel filter... Do you always have to drive like this to get good gas mileage?

 

i think i need a new o2 sensor from what im hearing right? and i think my tires need to be replaced..my car seemed alot heavier after i put on the SE rims...

 

intake suppose to help ur milage

 

check ur plugs