I have always gotten in the low 20s mpg with my truck. This last month it has snowed a ton in Colorado and I haven't had the front end disengaged at all. I have gotten the worst mileage ever in the 10 years that I've had this truck at 17-18mpg. The low temps and resultant high gear oil viscosity mixed with stop-and-go really killed my mileage. Of course that includes the oxygenated winter gasoline and denser cold air. But I have never gotten under 20mpg before even in past winters (but I only had the hubs locked maybe 7 days out of the whole winter).
I had been thinking that maybe something was wrong with the engine but I just got 24 mph (highway at around 7k feet) this weekend with front disengaged which is what I get in the summer.
I guess cold weather mixed with stop-and-go and having that front end turning all the time really can affect mileage.

Oddly enough, I am noticing the exact same thing. My last tank has been dismal, with no apparent reason. Same driving, same everything, as far as I can tell. Usually about 20mpg, and I'd be suprised if I'm getting even 12-15 right now

Kinda sucks.
I wonder if there is some bad gas going around in Colorado. I'm in Fort Collins- where are you?

B

I have noticed my milage is lower and a lack of power with gas from certain stations. No snow here B P is very poor gas .I have heard they are mixing stuff in it for environmental reasons ,ethanol or something

There are lots of factors that decrease winter fuel economy. If you are like me, you start your engine & then go scrape ice or clean off snow. You get zero MPG while idleing & not moving. Cold engine oil, tranny oil etc increase drag until they warm up, & as you say, accidents & other problems increase time spent with engine running & no movement. The extra drag from using 4WD also factors in, but the mileage drops even in a 2wd rig.

I've been running both for over 20 years up here & I bet I could tell you more or less when the major storms came in by looking at the mileage logs.

Dave

every gas station around here has 10% ethanol in their gas year round. i always thought bp was good gas, but maybe its just my imagination. crown gas on the other hand, it has dirt in it. no joke.

Two other things that could impact it:
1) If it takes a long time for your truck to come up to temperature.. When the engine is cold, EFI adds more fuel to the mixture.. When really cold, it's actually a lot more fuel.

2) Intake air temp again, more fuel when cold to compensate for dense air.

ya, i went from best of 23.5mpg in early December to current low of 15.5mpg. All this with the same tire pressure/size/ratio/hub unlock. Crazy i tell you! And yes, i live in Quebec and I start engine first for 3mins-ish while i'm scraping snow/ice.

Still, 8mpg differece is too much!


<img src="/forums/images/graemlins/scared.gif" alt="" />

Winter fuels are usually good for a 1-3 mpg loss, a 34% loss in mileage is a significant loss. Did you have adrastic drop in temperature?, if not, I would start looking into it, you may have a bad plug, injector or sticking valve, etc. Even letting iot warm up for 5-10 minutes wont consume that much gas to cause a drop like that in mileage.

This happens every year to me no matter what car I have had. The best solution is to plug it in over night so the engine isn't a brick in the morning.

Only from about 7-8?C (23.5mpg) to -10?C ish (15.5mpg), about 15? - 20?C colder. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />