Depressing Fuel Economy... :(

[SlowNA06]

24mpg is not bad, depending on the weight in the car. I always load my bags and such into the front seat if I have no passenger, or the backseats if possible. Junk in the trunk is a mileage killer. Every hundred pounds is 0.1 second off your 1/4 mile speed, so imagine what it does to fuel economy. Figure a road trip for two people is 500-600lbs load in the car.

[kingjohn1027]

Alignent was checked when the new tires were installed. No adjustment was needed. 91+ octane is always used. I have replaced the front o2 sensor. I hooked my friends Genisys evo scanner to the car. Everything checked out. No misfires, sensors all check out.

[kingjohn1027]

I also had the converter checked by two different exhaust shops. Both said it was fine.

[SlowNA06]

Air intake filter?

[buickman104]

How about a tune. When the seasons change my tune goes out of whack and my fuel economy drops. I re-tune it for the weather and I regain my fuel economy of about 31 MPG highway comes back.

[SlowNA06]

Both gps running stock tunes, though.

I think you two should switch cars for a day and see if the vehicles' mileage changes.

[kingjohn1027]

ISSUE SOLVED

I thank you all for your help. I took it to a garage in the city that does custom tunes. I am getting much better economy now! Two tanks burned thus far and averaging 28.2 combined mileage. Turns out the computer was making the engine run waaayyyyy too rich. Custom tune has rectified that. Thanks again for the help!

[Rico]

Congrats!

He must of leaned that thing out alot 'cause 28 all around seems abnormally good. What were the AFR's at WOT?

[buickman104]

Yay! My advice helped! Yup whenever the seasons change I end up having to retune to regain my fuel economy.

[ZachG]

I am averaging around 13.6mpg around town & 15mpg on the highway, i just had a tune up. i cannot figure this out either, any help would be good casue i average about 250 miles a week.

[SlowNA06]

Was it bad before the tune-up?

[ZachG]

Yea it was just as bad, the shop i went to said the car was perfect, fresh oil change and everything, and those numbers are from when i drive normally.