Very frustrated (winter MPG)
 

I've had my Jeep out offroading a bunch, which in itself isn't bad. Its nice to get away from people.

My frustration is that now its winter, I expected an MPG drop. What I DIDN'T expect was the almost 4MPG drop. And I haven't significantly altered my driving habits, other than slowing down a bit when its slick. I understand the fuel formulations change and that warmer air is better. And I didn't add that much weight with my extra winter carry stuff.

During one offroad trip I did have the vacuum line come off the MAP sensor, but when my CEL came on I did the key cycle check for codes, and it showed the MAP, sure enough replaced the line with a new longer (2" longer to allow for movement) hose.

MAYBE, I need to reset the computer. I am going to do an upper grill block fro the winter and see what I can get away with (Jeeps overheat WAYYYY too easy)...

WAI for Jeeps
 

I dont know how your airbox is set up compared to that of a Cherokee (XJ), but FastPlastic had an interesting and innexpensive way to get warmer air to the intake.

http://ecomodder.com/forum/showthrea...tml#post143271

Hope this helps!

Winter blend of gass, and cold air are bad on gas mileage.

Cold weather hurts FE many ways:

Greater air drag because of denser air (I remember 6% increase for 60F down to 30F)
Longer warm up time, so the fuel mixture stays richer longer
more resistance in bearings and tires because of low temperature
cold weather gasoline formula
greater electrical use: defrosters, lights, etc. (even A/C in defrost mode)
reduced traction, increased rolling resistance in ice and snow and slush and wet roads

4-mpg
 

A 3-mpg drop for a full-size passenger car would not be uncommon during winter.
You get an extra whammy from the transfer case and front differential gears wetted with temp-induced higher viscosity lube do to the cold.
I'd like to say that a switch to synthetic gear oil would help,but my own experiences with Red Line full syn and Mobil-1 forbid me to.
There might be a little comfort in knowing that everyone else with a vehicle like your's is in the same boat.
I'm down a half mpg in the T-100 so far.I'll lose another 1.5 mpg before winter's over.

zjrog -

I was happilly humming along with 44+ MPG in the summer, and now I am being baraged by lots of barely 40+ tanks. I thought it was going to get better, but now here comes a week of rain.

I feel your MPainG.

CarloSW2

If you look at my fuel logs, you'll see about a 30-40% drop in FE during the winter. It's a big sucker. Just gotta wait it out (or migrate south I guess).

Yes migrate to the south :turtle:, no change in temperature down here. It is almost always 80+. Last winter, sorry I ment to say JAN, FEB, MAR i had to use my A/C several times, but this is the trick when the summer comes it's like HELL...:rolleyes:

I loose 5+ in the winter, and I am paying over ~5.30 a gallon, quitcher wining. I can't even blame mine on summer/winter gas as the tanks out here get filled over the summer and drained over the winter (our fuel is barged in) so it is a stable over time blend.

You guys know how to make a guy feel better... I use synthetics already, but don't recall a drop this severe last winter. I'll look into that airbox mod.

Moving south is not an option at this point (I really like Utah and snow). And bestclimb, Alaska is the only state I haven't been to yet... But when I do, it will be summertime!