[schap12]

I bought a used 335i about 3 weeks ago and i am getting 12mpg....its stock. what could be causing this.i drive 50/50 but even if i was driving it 100% i dont think the stock motor would have that poor of gas mileage. the car has 65,xxx miles i just bought new plugs but havent put them in. any input would be great thanks.

[Route 16]

Press/reset the mpg read using the stick, hold the button til it's ---

[PichaDis11]

Originally Posted by Route 16

Press/reset the mpg read using the stick, hold the button til it's ---

This..

The car is still calculating average miles per gallon from previous owner, who if not both you driving like you stole it... I saw 11.5 in my 328i the other day and I am almost certain it's just my 5 min drives to and from train station during the week.

[hardtothepaint]

It could be just what the other posters have already said. It is possible that the previous owner or dealership kept the car running on idle for a long period of time. Resetting the gas mileage should help. Don't forget to reset the average speed as well.

[norsairius]

To get the best calculation for what you're getting for gas mileage (I don't always rely on the computer, but it's good for a ballpark figure at least): I'd suggest going to the gas station, filling up your gas tank, and resetting the trip meter. Then go about your regular driving. Next time your car needs gas, fill up your car again, take note of the amount of gas dispensed then divide the mileage on the trip meter by the amount of gas dispensed. If you get a bad or unexpected number consistently, then you may want to get the car checked out.

[schap12]

thank you everyone i will reset it again, and calculate with trip meter

[Doctor///M]

If it persists, have your fuel sensor checked. Mine gave out and was getting similar MPG's. The bad sensor resulted in too much fuel being pumped to the engine.

[Taran.J]

If just bought have you done a tune up on it? But what the others suggested may do the trick too.