What is the CEL?

 

Check Engine Light

I've got about the same MPG, but I've got a part on order which I think will fix it (or so I hope). I also did a seafoam, and it appears to have helped by about 1 mpg, but I haven't actually calculated it, so don't quote me on it.

Just out of curiosity, jack up the front end of your car, turn the keys to the on position but don't go far enough to start the engine (this is to release brakes, as pressure can build up when car is off if the pedal has been depressed). Spin your front wheels and see if one resists movement more than the other. My driver's side wheel spins fine, but passenger side takes a good amount of force. If a similar scenario occurs to you, then take off the wheel and make sure it's not the caliper. If not, it's probably the bearing. I've got the bearing assembly on order, so I haven't made the change yet, but that could very well be both of our problems

 

No, the check engine light is not on. I will try checking the breaks later but it doesnt seem like there is any change in performance.

 

Its not the breaks. My friend suggested that it may be a defaulty 02 sensor? What are you opinions on this?

 

I only get about 150-230 to a tank but i drive it like a race car pretty much all the time...

 

I don't drive like i'm racing and it usually shifts out of first around 3K rpm. I really don't think that this could explain 65 miles on the first half of a tank.

 

try shifting at 1800-2100

 

Usually a bad o2 sensor trips the CEL light.

Tires properly inflated? You'd be amazed how much they affect fuel economy (not 10mpg difference, but I went from 19.5-20mpg mixed to 22.5-23 mixed just by adjusting my tire pressure)

You were getting the 250mi/tank with the tune, right? Or did the decrease happen after getting the tune?

I'm getting about 250mi on 3/4 of a tank (I don't usually let the guage go below 1/4 tank), but I have a manual so it helps with mileage a little.

 

my car used to do 250ish to a tank, these cars also do have puny tanks

 

i dont know what it could be then??? the CEL is not on, its not my breaks, spark plugs and wires are ok, i dont "drive like im racing", my tires are maybe just a tiny bit uninflated but how am i getting 150 miles on a full tank when before i was getting 250+??????????!!!!!!!! And to top it all off its getting progesivly worse.