Miles per tank question

[andonakis]

I have a 3.0 2006 x5 sport. Bought used July of 09. I have 59000 miles on it now. My question is, I've been getting on average 430 miles per tank. And then just a couple of months ago it dropped to around 330 miles per tank with no change in driving. Our winter temp has been below 32f, but do you think drop in temperature has a something to do with it??? 100 mile difference is huge. My mechanic says its because its time to do the service 1 at 60000 miles. I disagree. Any thoughts.

[hunds02]

are u changing your oil regularly? Are you using synthetic oil? Also if my memory is correct, u do need to do a check up service around 60,000 miles. Spark plugs tend to wear out by then. Its hard to tell what is causing that because so many factors can lower your gas mileage. But since you have an 06 and have 59,000 miles i assume you are still under warranty? If so it wont hurt to get the service at your local bmw service shop

[cheappc]

yes, inspection I or II is needed at 60,000 miles (i just got mine at 59,950).

Now about your gas... wow... using different type of gas?

[andonakis]

I'm using premium gas and on occasion midgrade. I'm using synthetic oil and oil is being changed regularly. I know I'm due for inspection I soon but I don't think it has to do with that because the drop has been sudden. When I fill up my range says around 440 miles more or less and to tell you the truth I have been getting almost that on average. But like I said earlier, now, when I fill up, my range would be around 440 miles but would need filling around 330. In other words I used to get average 18mpg down to 14mpg. I'm getting my service done soon so I will post if it made a difference.

[motordavid]

I don't think it is simply because you are approaching "Insp ll" mileage...

Have you checked your tire pressure in this colder weather? They may
have dropped below 32 or, even 30 in the cold.

Are you doing "mpg" based on fillups/arith, both "before" and now with
the less range?

I suspect cold weather, maybe a dirty air filter, maybe a MAF, but cold
weather...my guesses.
GL, mD

[Werewolf]

I believe 60K is inspection II the bigger of the two services.

Re: MPG. you've got a 25 gallon tank give or take. 20 x 25 = 500 theoretically. 330 sounds bad.

Maybe do the easy things and see if the MPG improves
- air filter
- clean the MAF
- check for vacuum leaks
- run some fuel injector cleaner

[andonakis]

Thanks will try all that. Plus going in for my first major service very soon.

[sprocket1200]

winter tires will give you worse mileage too. it is clearly cold enough that you should have them.
parking brake out of adjustment?

since you are getting such worse mileage, i would take it in for an early inspection II. pull the codes and see what it says...

[PeteHubs]

Okay one more thing that no one else has mentioned, your in a colder climate so I'm sure that your gas stations are using a winter blend of gasoline, they add more alcohol and other stuff to allow it to run better in the even that it gets really cold...

Hope that may help, there may not be a imminent problem after all

[andonakis]

HMMMMM...... winter blend gasoline. Well that could make sense. I live in the southeastern part of Tennessee so our winters are pretty mild except for this year. It's been colder than normal as of much of the southern states.