tuffluck

i've had my 2007 530i for about 6 weeks and i had one highway trip where i got 29mpg, but all of my city driving is bad. i got 15.6 on one tank and 16.6 on another tank, and my most recent tank is at 40 miles and the OBC is showing 14.8. i don't typically drive in drive sport, but i do live in a very busy city, so my city driving is true city driving in most cases.

the only things to note are that for starters, i live less than 2 miles from my job. so my commute to and from work is 2 miles with about 4 stop signs in my way, plus in that distance i doubt the car even warms up fully, which could have some impact. otherwise my in-town driving is just 5-6 miles a day at most to the grocery store and to run errands and such. i think on both the 15.6 and 16.6 tank i made a 20-30 mile trip that was mostly cruising 70mph on the highway, but otherwise the majority of my driving is pretty intense city driving.

just seems low to me. especially since it's rated at 20/30. 29 on the highway is great, but the city is poor. what are you guys experiencing? i think the 2006-2007 530i experiences are the best to hear from since those were the only 2 years with the 255hp version of the I6. also might be important to list the TYPE of city you live in. city driving in rural mississippi is probably not the same as urban dallas.

i think it might be worth asking the next time i'm in the dealer for warranty work to do a fuel filter replacement or something and tell them the mileage is pretty low.

Howitzer

First thing I'd do is replace my spark plugs. I did that at 50k miles and it made a huge difference. Second thing I'd do is clean my Mass Air Flow sensor located in the air tube connected between your air box and your engine. Remove it with 2 screws and spray it with MAF sensor cleaner you can get at AutoZone for $5. Well worth it. Third thing is get a BMC or K&N air filter. Allow your engine to breathe more freely with a quality air filter!

With these 3 things you'll notice a change in your car's behavior.

P.S. - If you haven't changed your oil since you bought the car, do it. If you want to really go all out go to the dealership and pay $140 for the BMW Fuel injector cleaner service. It was great on my car when I did it to my 530i. Also, fuel filter replacement is a no-no and not needed AT ALL for the life of your car. Its a huge waste of $$$$. If your car is near 70k miles I'd also get the transmission fluid changed. When your dealership tells you "its lifetime fluid and sealed" tell him to STFU and change it anyways.

tuffluck

oh thanks for all that! very helpful. for starters, i have only 46k miles and my car is still under the factory warranty. the car is also a CPO so at 50k or 2/2011 (at my driving habit of >200 miles a week, february of 2011 will probably come first), so i will have the CPO warranty after that.

under warranty can i *ask* them to change the spark plugs? usually that is the kind of thing they won't do until the idrive tells them it's time to replace, or so i thought. any help with getting the dealer to do some of the things you mentioned would be really great, though i doubt they will clean the MAF or use a K&N no matter what.

also i would expect with a CPO they change some of the common wear items and maintenance items like oil and spark plugs. is there anyway i can check on that? i know the idrive says how long until you should service certain parts, though that doesn't really tell me when they were serviced last.

lightfytr

They wont change your SP's (unless something is wrong with them). They wont clean your MAF. CPO will does not cover common wear items.

I attached the CPO book to explain further.

jjtitus

Ive never changed spark plugs in any car before and I did it in my 04 530i. Pretty easy if you ask me. Just set aside 2-3 hours at least to do it and take your time. Much better than paying someone to do it. Cleaning the MAF is easily something you can do yourself... only takes 5-10 minutes. No need to have the dealer do any of it.

tuffluck

i'm aware the cpo doesn't cover common wear items, but i am still under the factory warranty for now. i got a cpo because it covers the more serious things. spark plugs are no big deal thing for me.

chris.y

I get about 24-25 mpg in a mix of 75% (sometimes stop/go) highway and 25% city (SF peninsula).

15-16 mpg sounds pretty low for an 07 530i, regardless of your driving pattern.

tuffluck

it does sound low, but i don't think 24-25 is all that unexpected for the driving you do, either. i would guess i would get similar mileage if i drove 75% highway. like i mentioned, i got 29 on the highway trip i took, so it doesn't appear anything is WRONG. and if it is wrong, it's something that is only affected by city driving patterns. the first one in my mind would be driving too hard. but i don't do that, so i'm kinda stumped and that's why i'm trying to get a rough estimate of other peoples' experiences. thanks for the input.

53007s1lv3r

I got a mixed 23/24 mpg on local/ highway.

Diamond

I think you are right on-I average 16 when I am doing purely inner city, mucho stop signs and lights and stop and go traffic. On the highway at 80 I get 33mpg so your highway is a bit low.

First thing I would start with is not your spark plugs--that makes no effect on fuel milage at ALL. Factor warrnaty dont cover those until 100 which obviously never happens since warranty ends at 50

Increase your tire pressure and not sure if you have sport or not but get a new set of bigger/wider tires. SUCH a bit misconception that skinnier tires get better gas mileage-which is totally opposite--skinnier tires have much more deformation at speed which loses heat/energy and costs mpg. The fatter the tire the less deformation and the better mpg. A contact patch is exactly the same area with skinny or fat--the shape only changes so some will say skinny is less because less material is touching the ground to drag friction-again not true. But higher pressures will help you as that actually lowers the contact patch and further decreases deformation and energy loss.

Getting a set of lighter wheels and tires--I started getting 2more mpg when I changed out my tires and wheels and saved about 10 pounds each wheel/tire--rotating mass is a killer for mpg and performance.

Also you are likely getting WORSE milage driving in D--this car is funny and gets wayyy bogged down in the low rpms--it takes more gas when you stay at the lower RPMS for too long as your engine is just fighting to move but really not going anywhere and it takes you longer to get to the speed where you no longer are acclerating and are cruising--and not using much gas. So DS and a bit more aggressive driving to get the rpms up more quickly (within reason obviously) you will see better mileage

A few small things is getting a fuel system clean at bmw for 150 bucks or so-They flush and pressure clean your fuel system and injectors. After that make sure to use a Chevron techron (same that bmw uses) every 3-5k miles of fuel system clearner to keep your injectors clean and carbon deposits gone.

Mkae sure you are using 93 octane or 91 in cali-that will actually give you better mpg than lower octane on this car.

My bet is if you increase your tire pressure-I have always gone 40 rear and 36 front and that should gain a couple. Other than that you are exactly where I am--I never understand how people get above 20 with city driving-atleast for my stop and go that just has not happened in 4 years!

This car is impressive though I can cruise at 65 and get within 1mpg as driving at 80 on the freeway and get 33mpg---that is the cool part. In the city when I go short distances I dont care about getting crappy milage as its so few miles. But long trips to be able to get 33mpg on a car that also can be fast and a lot of fun when pushing it is a cool deal--