Yeah,the whole methanol thing sucks;I had to run premium in my Eclipse and it suffered about a 20 mile a tankful loss during the winter months. I think the "ethanol season" is from October to March around here.

 

you have got to be mistaken! to the quarter mark!? lol, unless i am mistaken, that would be around 7-800 miles per tank!! lol whadya got in that thing an RV gas tank and a FCX fuel cell engine!!? geez

 

How's your tire pressure? With 35's you've got a lot of volume. As the temp drops, so will the relative pressure inside your tires.

 

The most I've gotten for my first quarter (when the tank is full) has been roughly around 100 miles. This was also the same time I got 200 miles for the first half tank. Normal city driving, with about 35% percent highway driving. Which ended up resulting in 17 miles per gallon. Not bad considering its a 3.0.

I cannot imagine how anyone can accomplish 180-200 per quarter (big difference between PER quarter over FIRST quarter).

I don't think not even the 3.4L can get this kind of mileage per quarter tank; correct me if I'm wrong.

 

Kyle, I meant quarter tank mark, not three-quarters mark. From full tank to three-quarter I get around 70 miles and at 1/2 tank I get around 120 miles.

 

i'm pretty much the same here in CA, using 87 ethanol gas (from 76, no MTBE), with 3.0 automatic. 70 for 1/4 tank, 120 for 1/2 tank, and 240 when the light comes on.

mind you, this is mixed driving, year round, easy on the gas pedal, without my roof rack. when i add the rack, i usually get about 220 when the light comes on.

i have the stock 31" with 4.88 i guess.

 

here in the *ahem* wonderful sierra nevada mounrain range, i always get worse mpg when its cold. i do have an honest answer for you though, colder air = denser air. denser air = more fuel charge. more fuel charge = worse mpg. simple as quantum thermodynamics. =) anyhow, the additives that gas companies put in "winter mixtures" does in fact reduce gas mileage, but in turn is supposed to help with cold starts. I dont know exactly what they put in there, i'm sure its possible to find out, but i do know that it does accelerate the breakdown of rubber components, so be sure to check those in the springtime for fun in the sun later on!

 

Gas companies do change the formulation of gas in the winter. It is to decrease emmisions and mileage always goes down 10+%.

 

In addition to the above, here are a few more reasons........denser air is harder to drive through.....thus the engine has to work harder to push your truck through the denser air. Since the engine works harder, it uses more fuel, this is what causes the "more fuel charge" that Satchmo724 mentioned. Also, in the colder weather, everything shrinks. All of your bearings and moving parts thus have more resistance and it takes more power to over come this resistance. Your lubes and oils also are thicker in the cold and require more power to over come the increased resistance.

David