Bad MPG in my XI... is this normal

Originally Posted by SamDoe1

BUT, it's not about how much air is pulled in, but how easily it is pulled in. If you choke off the end of a vacuum cleaner, or restrict the intake, the motor works significantly harder to pull in the same volume of air. ... So while the actual amount of air in the intake charge wouldn't change, the amount of efficiency lost from a dirty/clogged filter would have an impact....You will, however, gain a few miles per gallon because of the change in efficiency.

The air cleaner does not "choke off air". If the engine needs more air, the throttle body opens wider. The TB is a much greater restriction than any dirty air filter.

I know it sounds like a clean filter would offer better mileage, but the facts do not support this claim. Trust me on this one; or Google "dirty air filter mileage myth" and read for yourself.

i get 27mpg if i try to drive good on the highway. BUT, i drive like an a-hole so i get 18mpg highway and usually i get 16mpg city but today i saw the thing in the dash and it said 14.5mpg... prob due to winter gas and excessive idling while cleaning snow off my car.... and single digit weather in the AM when i drive.

car fully tuned up 1 month ago (new filters and sparks)

SamDoe1 - would love to get your mileage...how do you drive, speed, hills or flats, mods to your car, air pressure, anything else that contributes to your great mileage?

the car is an overweight slug for the poor 2.5l

I get 25.5 mpg in my 2003 325 xi wagon (freezing temps) and 26+ normal temps, but I drive 90% highways.

Loss of mpg might mean oxygen sensor problems...?? (Costly job to get done from what I hear)

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I also noticed driving style really does affect the mpg (I have a lead foot in general, but I try to be good. The difference can be 5+ mpg difference. (Tring to be good since I have to save money now that I'm going through a divorce)

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My auto 330xi gets an average of 21mpg combined city/highway on average light foot driving. But enthusiastic drives average about 19mpg.

Get about 24mph in my 325xi auto mostly highway driving around 75mph

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Originally Posted by TwoDuckDad

SamDoe1 - would love to get your mileage...how do you drive, speed, hills or flats, mods to your car, air pressure, anything else that contributes to your great mileage?

Well I don't drive it like I stole it but I do wring it out every so often. I like to think I drive "normal" as in I keep up with traffic, I'm not the a-hole in the left lane doing 95 in a 60, I don't floor it and slam on the brakes every chance I get, but I don't drive like a grandma either. Traffic is traffic, there are times where you can cruise openly at 65-70 and times when you stop and go for 5 miles. I have zero engine mods on the car, stock air filter, stock spark plugs (which reminds me, they need changing as they have been on there since it rolled off the line), stock everything. Goodyear Eagle RS-A tires (crappy, don't buy them) at around 35psig all around. Driving route is a good combination of hills and flats, I live in the twin cities area in Minnesota if you're familiar with the area. My long distance drives typically consist of a route from MSP to Milwaukee, WI which is a straight shot down I94 at ~75mph the whole way (cruise set).

2001 330xi fully stock w/ the exception of the 19" wheels - 1K road trips get me about 24mpg w/ the cruise control set at roughly 70-75mph. Around town, I'm more likely to get about 19mpg.

About 25 mpg in my 330xi auto mostly highway, 50 miles every day driving with no rush ( 70-75 )

I have been getting 25 to 26 with 80% highway driving (70 miles per day) I definitely try and conserve fuel with the commute, but I have gotten as low as 23 mpg with more city driving. No OBC, just manual calculation.

I agree with SamDoe1.
My 325XI-2002-166K miles, auto, does same mileage : " Also, I get approximately 24-26mpg driving to/from work in rush hour stop and go traffic. I get 32-35mpg cruising on the freeway for 5 hours straight."
No mod, all stock, new spark plugs, Synt. oil, normal drive, cruise control on HW ~ 70-80.

Originally Posted by dephantn

I agree with SamDoe1.
My 325XI-2002-166K miles, auto, does same mileage : " Also, I get approximately 24-26mpg driving to/from work in rush hour stop and go traffic. I get 32-35mpg cruising on the freeway for 5 hours straight."
No mod, all stock, new spark plugs, Synt. oil, normal drive, cruise control on HW ~ 70-80.

35mpg on the highway? I'm not buying that.

Get gas before and after a 100 mile highway trip, and divide by gallons. No chance you are getting 35mpg in an auto xi. No chance.

i thought i was getting poor gas mileage based solely on the obc mpg. it said 21.5 mixed highway and city. i calculated my actual mileage based on the miles i drove divided by the fuel in the tank and i got 27.5mpg. i'm not saying it's right, but i'd expect it to be somewhere in between 21.5 and 27.5 which is fantastic.