ubernixon

hey guys,

I own a 2004 530i

In the past few fill ups I've been getting lower mileage, used to get about 340 miles and now its closer to 300. I've had a tune up a little over a year ago so the plugs and wiring etc. should still be good, tire pressure is good, use good gas, oil changes regularly.


I was going to look into replacing the thermostat (I believe there's two of them), not sure how to do temp tests. Anyone have any insight on this DIY. Maybe cleaning the AFM sensors or something.

or any other probabilities,

any help is appreciated

-mike

AchtungE60

AFM sensors? Is that what you guys in CA are calling it these days? I think you're talking about MAFS (mass air flow sensor)
How many miles? give some stats on the car...perhaps your fuel filter should be changed out.

ubernixon

Haha

Yeah thats what I ment

I'll look into the filter as well

Thanks

luigi524td

Cold weather will certainly reduce your fuel economy - as will any (even minor) change in driving style. You've looked at the other item your tire pressures. Not unusual for them to drop 1-2 psi for every 10 degrees the ambient temp drops and it's January in Canada - No global warming is there ;-) Low tire pressures can easily drop your average mpg 5-10%

AchtungE60

well i dont think the MAFS would be the culprit...definitely check the tire pressure but also let us know how many miles you have because you should probably be in the 100's by now and perhaps your filter is a bit dusty

pcy

Depending on which gas station you use, 10% ethanol is part of the winter blend. You can expect reduced mileage with 'winter blend' gas.

Low tire pressure can contribute to poor mileage. During winter, first few minutes after startup, mileage will be bad until the engine warms up and goes to closed loop. So, if you are making short trips, you can expect poor mileage.

ubernixon

The. Car has 110k kms on it, so around 68k miles. I'll definitely check out the oil filter. Last winter I didnt notice a change in mileage, I live in Vancouver so its not really that cold. My FTM warning came in this morning so I'll check my tire pressure, but that's just because some f@&kin idiot reversed his truck right up onto my hood this morning. Like 4k damage..... Anyways

I think I got that acronym right

ubernixon

.... I ment fuel filter...... I suck