pjinca

Ok, so back in Feb I had the oil changed and Inspection done (iDrive said I was close to needing both 500 miles to go on each). My car has 55k miles on it now. Since the oil change my mileage has gone down to a sickening 16.5 mpg down from 21.9 before the change. What could be causing this? Sparkplugs? Clogged injectors? I drive the same way as before, although my commute involves a little more street driving now since buying the house.

vickp

I had the same thing happen on '06 525i manual. It constantly showed around 25 to 27 mpg but after in combined driving (little bit more of highway than street)but after the oil change & reset it has never inched passed 22 or 23 mpg part of it being i drive on street more so now than before and the computer calculates the average consumption every so many gallons a tankful. If you go on a long trip (400 miles or so) u will see it creep back up and after that the average mpg will stay up there because it will factor in your long highway trip average with the most recent mpg as well. So don't worry about it, everything is fine or take a good long scenic trip to prove me right.

stock545i

Add to your list.. low tire pressure, cheap gas, dirty air filters. I'm assuming car is running smooth? If it has 55K miles on the plugs, could it be? Do you get any condensation in your exhaust tail pipe when you warm up the car in the morning?

And finally - LEAD FOOT?

vickp

i am in SOCAL and have noticed i do get condensation fumes on the exhaust pipes but only when the weather is cool. u think there is something that i should get serviced ? i thought it was normal due to mileage, i am at 57000 miles right now.

manaiauds

I'm also getting the same mileage 14.6 mpg/city and condensation is present in my tail pipe when I warm up the car in the morning. Just had an oil change, filter change and transmission oil change.

or_550i

You must find a reason to drive longer and burn out that water. Seriously.

bens1088

14.6????? ouch.....

pjinca

Hmm, I will be driving to Vegas on Sunday so we'll see what happens

Let's see, tire pressure is at 35PSI (20" recommended pressure), gas is ALWAYS Shell V-Power 91 (max in Cali), Air Filter is a relatively new K&N and I just cleaned my MAF when I replaced it. Car is running as smooth as ever no condensation unless it's below 55F, Oh and as I said originally - I am driving the same way I always have been.

pjinca

Okay 14.6 makes me feel better - thanks

EBMCS03

I think thats your problem right here... more streets... it take a lot of gas to get the car moving from a standstill....