Really bad gas mileage

[Dan_SF]

I recently bought a year 2000 318i (in Europe) with an automatic transmission. I only got about 17 miles per gallon driving mainly in the city. I took the car to a BMW dealer and I was told the engine was fine. They changed the air and gas filters and changed the spark plugs. The gas mileage is still bad. Any guess why it is the case? Thanks.
P.S. I forgot to mention the fuel consumption gauge shows a much higher mpg (about 24-30 mpg range) when I drive.

 

[selavia]

driving style? When I drove mine rough in the city I would get around 20 mpg.

 

[selavia]

ALso, tire pressure (but that shouldn't have such a drastic effect).

 

[sidvicious]

mine recently had a computer issue, then seemed to fix itself.

i average 27 mpg. yesterday, all the sudden, the consumption readout was about 5 mpg lower. after clearing out both consumption 1 & 2, the correct readings returned, and it is inline w/ the analog guage. i've also tested it realtime and the readout is correct at 27 mpg.

 

[john r]

My european 1994 Auto 316i gives 20 to 25 mpg thats combined in/out city, if I was doing mainly city driving I reckon the mpg would be 20, your 2000 318i sounds a bit heavy try not to accelerate to the point where your injection kicks in & don't use your sports switch in the city.

PS my needle shows over 30 mpg when driving but I guess when I stop & start at lights the mpg is heavier

 

[epj3]

My european 1994 Auto 316i gives 20 to 25 mpg thats combined in/out city, if I was doing mainly city driving I reckon the mpg would be 20, your 2000 318i sounds a bit heavy try not to accelerate to the point where your injection kicks in & don't use your sports switch in the city.

PS my needle shows over 30 mpg when driving but I guess when I stop & start at lights the mpg is heavier

I agree dont drive it till the injection kicks in, otherwise you'll get great gas mileage with the injection system is off, like almost infinite gas mileage.

 

[nadroj]

I agree dont drive it till the injection kicks in, otherwise you'll get great gas mileage with the injection system is off, like almost infinite gas mileage.

dude keep the injectors off and change your headlight fluid

 

[codex57]

Yikes, that's about as bad as my 2.5L 6 cylinder. What did the mechanics check on your car? Compression or some of the more in detail engine checks? Maybe dirty fuel injectors?

 

[Cats_fender]

I used some redex for cleaning petrol injectors a few weeks ago and there seems to be a drastic improvement in my petrol mileage.