Within the last two months I've noticed that my combined mileage is about 24mpg down from about 32mpg. I know there are several factors that could be impacting this such as winter blends of gasoline, the extremely cold temperatures of late, and the fact that during the week, I drive 3 miles to a train station and 3 miles home, that's it, so the engine doesn't have time to warm up fully.
What I'm wondering is why this winter I'm noticing that big of a drop when last winter, (same driving habits) I didn't see the drop.
Is 24mpg (with mostly short distance driving) normal for winter driving on a 07 Civic with 107k miles?
Would the fact my transmission hesitates to shift up to 5th gear (until the motor is warm) have something to do with it? The transmission was just serviced 3k miles ago (and 2k miles before that due to a different Honda dealer overfilling the transmission by 4qts when they performed a transmission service). I was experiencing a loss of MPG when it was overfilled.
Would having the valve timing adjusted help at all? During the 100k service at my local Honda dealer they recommended a top end tune up (which included a valve timing adjustment). I declined the service because the engine seems to be operating fine.
Would it be worth running a fuel system cleaner such as Lucas to see if this helps? I just filled it up with premium gas to see if that made a difference, it didn't.
have the same problem?
Tuesday, February 17th, 2015 AT 7:04 AM