Terrible Gas Mileage on 128i

[Dackelone]

Originally Posted by maxnix

In the same driving conditions? Not likely unless a lot of highway is involved.

Winter warm ups kill mpg anyway.

And the "winter fuel blends" if you live in/near a (big)metro city that gets EPA reformulated fuel for the winter months.

[sixburgh]

Tell me, how do you "reset" the computer?

[sixburgh]

went to the dealership today to see what i need for scheduled maintenance. it was impressive technology to see the technician take my car key and see the information as to what maiuntanance is needed... a scheduled brake fluid change is now scheduled! The tech also told me i have 32 miles left in my tank...
I asked about the poor gas mileage. He said the 128i car is just so light and this contributes to the poor mpg's. Maybe a constrictor plate for the fuel is needed? Lulz.

[mleskovar]

Originally Posted by sixburgh

... He said the 128i car is just so light and this contributes to the poor mpg's.... .

This statement doesn't make sense

[Tom K.]

Originally Posted by sixburgh

Tell me, how do you "reset" the computer?

Scroll the OBC so that Average MPG comes up and then hold the end button in until it reads "---" (if you are stopped).

Better still, read your manual!

Tom

[Iron Man]

Originally Posted by sixburgh

I asked about the poor gas mileage. He said the 128i car is just so light and this contributes to the poor mpg's. Maybe a constrictor plate for the fuel is needed? Lulz.

Yeah, you know because the heavier you make the car, the better your gas mileage should be... Try putting some lead weights in the trunk and your mileage will improve.

[Dackelone]

Only major errors (CEL) faults are stored in the key fob. Your tech really should read your engine ECU for faults. He should also check the lambda values to see if your engine has a vacum leak, and your engine is trying to compensate by adding more fuel to make the engine run. Lambda values should be dead near 1.00 +/- 0.02

Have you checked the simple things like proper air pressure in your tires and a clean air filter? ???


Dackel

[NIB]

Originally Posted by MikeinAlexandria

My car consistently gets 29-31 highway at 55-65mph. But around town in light traffic with stop signs it averages 19mpg. I could see getting 12-15 if the car was in stop and go traffic for several hours a day (we have that here around DC, but I don't use the car to commute), or it was being driven at high rates if speed (100+mph) or at high rpm (over 5000).

I would check the air filter to see if it is clear and reasonably clean, and maybe remove the spark plugs and check them out to see how they look.

Mine Car 128i Convertible 2009 model, has been stationary for some time in a dealer shop before I bought it and it has 8.5mpg average on it. I have not flogged it for touring yet nor use it intercity for mine runs, but the few times I have taken it out with the roof down, I feel hot air from under the car around me. I want to know first, is this 8.5mpg alright and the hot air from under is it normal..

[NIB]

Originally Posted by Dackelone

It will get better once the engine breaks in after say 5K miles. Its also because you probably have a lead foot right now and are enjoying your "new car".

Mine 128i with 37,500km was averaging 7.9km/l and I entered a pothole at speed, the Check engine, ABS, brake light and DTC light came on and I took it to mine Mechanic. Diagnosis was carried out and I was told to change the rear left wheel ABS Speed sensor, the Ignition coil and Plug and do an alignment after. All this has been done with stock parts. When put under the OBD2 Machine with intent to clear the error, it was still giving the following codes, 94C2, 94C7 and 5DB6. I have not done the alignment yet. Please what are the meaning of the fault codes.

[NIB]

Originally Posted by Dackelone

It will get better once the engine breaks in after say 5K miles. Its also because you probably have a lead foot right now and are enjoying your "new car".

Hi Dackelone. I am averaging 24litres/100km and in traffic most of the times I take the car out. Is this good. I have changed the Ignition Coil, Plugs and Air filter. If not good fuel consumption rate advice on what next I should do.

[Dackelone]

Originally Posted by NIB

Mine 128i with 37,500km was averaging 7.9km/l and I entered a pothole at speed, the Check engine, ABS, brake light and DTC light came on and I took it to mine Mechanic. Diagnosis was carried out and I was told to change the rear left wheel ABS Speed sensor, the Ignition coil and Plug and do an alignment after. All this has been done with stock parts. When put under the OBD2 Machine with intent to clear the error, it was still giving the following codes, 94C2, 94C7 and 5DB6. I have not done the alignment yet. Please what are the meaning of the fault codes.

I think those codes are for the steering wheel sensor. The SZL sensor might need to be reset...

DSC Speed Sensor Error caused by bad Wheel Bearing?http://www.1addicts.com/forums/showthread.php?t=722556

[jaye944]

no at least 24

Originally Posted by AdmiralAdama

just got my 128i and after 1000 miles im averaging 15mpg in mixed highway and street.

Is this normal? And why is the 128i getting such bad MPG?

[jaye944]

Originally Posted by sixburgh

I asked about the poor gas mileage. He said the 128i car is just so light and this contributes to the poor mpg's.

^^^^ is rubbish, if it where correct, a lighter car has less weight to drag around and would give better MPG

[jaye944]

Originally Posted by Dackelone

and a clean air filter? ???


Dackel

^^^ this, first thing I did

[jaye944]

oh winter tires, winter driving and weather will lower your MPG' but not by that much

[NIB]

Originally Posted by Little1er

I have a 135i and my friend has a 128i. In SF, I get better MPG's than him. I get around 14, he gets 8!

Sorry it is a late thread, but are you serious at 12mpg and 8mpg with no vacuum leak, misfire, idle, high lambda value. Well I am averaging 11.4mpg with a lambda value of average 2.0 pre CAT and 0.68 after CAT. Well for mine I am sure I have a problem somewhere.
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