I just noticed on my way to work tonight that my avg. mpg's went from 15.2 this morning on my way home to 11.8 tonight. no i am not towing anything or i didn't idle for a long time. i do need to change my oil, but i didnt think it would make that much difference that fast. any help would be great. Thank you.

 

It's the nature of the 'beast'. Nothing you can do about it until Spring.

The colder outside air temps causes the PCM to richen up the fuel mixture plus all the gas stations are now pumping the winter blend fuel. These two combined will cause a 2-2.5 mpg decrease.

 

My mileage has lost about 2, it is the winter blend.

 

As others have said. winter blend, colder temps. My 09 drops to 11-12 in town during the winter. Seems the hemi really hates short trips.

The highway mpg seems to stay about the same for me no matter what time of year.

 

Yeap getting 10 around town now in my 2500 hemi

 

Not only the Winter blend, but the remote starter too. Man that things kills the mileage if your waiting for the truck to defrost the windshield like I do 'cause I'm a lazy Mo Fo.....

 

Yep, (low) 12 mpg's, here we go!

Usually sitting around mid to high 14's outside of winter blend, especially with cooler temps = horrible mpg's.

 

What are the thoughts on replacing O2 Sensors in older vehicles. No Ck eng lite but newer tech allowing them to go to closed loop sooner??