Anyone experienced this? I went from 22+ mpg to 17 seems like overnight. No noticeable performance changes. No changes in driving routine. Changed air filter... no change. Colder weather has set in but that's it. Any ideas????

 

probably the cold weather. Idle is different and car will run very rich at start up b/c its so cold. Join the club.

 

Perhaps the gas is different? I think about 8-10 years ago, the gas mixed with MTBE caused a 10 percent or so loss of gas mileage..

Keep an eye on it and see if the mileage remains low for the next tank or 2..

 

gas is different(drop 1-2mpg), you probably (and should) warm up your car longer with the colder so you waste gas there too.