Decreasing MPG

[steel21]

My 2004 325Ci is recently has a steady drop down to 23.1mpg, does this have anytihng to do with the cold?

Speaking of the cold, when i start the car these days, it usaully sort of Rev up for a while, so I usually swith over to manual until the motor warms up a bit, is this normal?


I appreciate all help , Thanks.

 

[Average Jae]

cold weather starts do rob you of mpgs, since the engine is less efficient until it gets warm. and car warms up easier in the warmer weather. duh!

you prolly wanna check out warm up thread and draw your conclusions there. i don't like to rev over 2.5 to 3k when the car is not warmed up.

 

[steel21]

Hmm...

Well, I was reading the Warm-Up thread, and thats exactly what i did. I never rev it above 2.5 before the needle is center on Temp. The decreasing MPG wouldnt be a problem except that I had just recently (2 weeks ago) replace one of my coils because it was misfiring. And ever since, the MPG has been decreasing.....does one have anything to do with the other?????

 

[MrElussive]

To warm up the engine, here are the rules:
-Drive gently (4K rpm should be the limit, although I like to stay below 3K).
-Don't drive at highway speeds.
-Don't free-rev the engine too much (i.e. drive around to warm it up, don't let the car sit there while you rev it up).

As for decreasing gas mileage, that's probably due to the colder weather. Also, make sure that your driving habbits are the same. To get optimum gas mileage, try not to gas it hard from a stop...that's what really affects your gas mileage as it takes a lot of engine power to get the car moving. Try to get up to speed before you accelerate more aggressively (if you care about gas mileage that much, that is ).

 

[steel21]

Gas mileage doesnt matter, what matters is that...

Gas mileage doesnt matter, what matters is that... it might be indicative of a loss in performance. And it worries me that it revs up so much without going anywhere when i start it up.

Ie, when i start it up in the morning, it would rev to around 2K without barely moving a foot? So i switch to M1 until i feel engine is ready for Drive.


Thanks!!!