I seriously don't think it's the cold weather per say. Hell my gas mileage increased when it got to freezing temps (because I was driving slower for the road conditions). If you're sitting there at idle all day until the temps reach temp gauge is 3/4 of the way up or higher, than yea that's it.

On warm ups, I just drive reaaaallly slowly until the temp gets beyond the marker then progressively drive more "normal" as the engine gets closer to normal operating temperature. On cool downs--I've never used my turbo timer--I drive nice for the last bit of my trek and don't hit the boost--which should be sufficient from what I can tell (and what I've been told). I keep my tire pressure at around 35 psi front to rear, keeping constant check of them (habit from riding sportbikes). My gas mileage still averages at 20mpg.

Bad gas can do it, bad driving can do it (that's accelerating faster and/or stopping faster). Not keeping up with maintenance (I.e. filters, plugs, etc.). Lots of stuff can cause it.

Here's an option for you though:

I read an article once in import tuner or honda tuner or something about the tuning of engines. It was right around when the gas prices started to skyrocket. Some people opted to specifically tune their cars for better gas mileage at the local dyno. (Probably specific to a particular RPM -- like 3k). It's somewhat counterproductive in certain aspects of trying to gain more HP--but it will help your pocket book if you're concerned about the MPG.

Article mentioned can be found HERE.

 

No worries - same story here. But I know I need a tune + winter, so I don't worry. Keep Evo in the garage during this crapy weather

 

chack your plugs after i changed mine big diffrence!

 

Winter gas can hurt about 3 mpg. get some Chevron Techron to clear out your injectors and fuel system.

 

Are you logging your AFRs or monitoring what load you are hitting? You may be in higher load cells than in the summer and running extra rich...That is my guess, along with lower tire pressure and winter gas, your MPG will decrease.

 

I am just the opposite. I just got my best tank ever with my stock Evo, 18.9 mpg. I am usually between 15-17 mpg. I have 8500 miles on my car.

 

On my last tank I got ~23.5 mpg

What kind of gas did you put in?

 

I tend to get around 20mpg in the winter but I've noticed that certain gas stations fuels will get me better millage than others. So far I've been having good luck with a chevron station and shell.

 

Just out of curiosity for you guys that are getting 22+, what method do you use to measure your MPG?

I.E. I fill up the tank--topping it off--after the tank I log my miles and fill up again; I then divide the number of miles by the gallons added. So for example lets say that first tank got me 265 miles. My subsequent fill up was topped at 11.5 gallons. That would get me 23.04 AMPG.

The flaw I see in this method is that if I filled up more the first time over the following fill up--the end result would be skewed because it will give a seemingly higher AMPG. But I try to always use the same station, same pump, and top it off the same amount of times (which is usually 2-3 times).

This could also be why some people are getting 23mpg, and some 20mpg--simply due to the division.

 

16.6 mpg for me. Maybe since the cold air is denser, the ecu compensates by adding more fuel. I'm sure this is good for racing, but for my daily commute, it's expensive.

 

Mrevo, the consistency if mpg results definitely relies on the fact that the pump shuts off at the same time everytime when filling up. Ofcourse this is not always true.

As for the thread creator, during the winter do you let your car sit to warm up before you drive it? Letting it idle to warm up will definitely decrease your gas mileage. Even if you don't let it warm up and start going right away, the engine is not at its optimal operating temp which could likely lead to less than optimal mpg anyway. The winter gas has its adverse affects as well like everyone's been saying

 

That's exactly my point...it's not consistent; which is why I posed the question. Too many variables involved to know exactly what is causing it--I'm sure it's probably a combination of the aformentioned items.

 

hmm.. strange, i never notice a different between winter and summer, i always get around 18-19 mpg no matter what...

 

I've noticed my mpg went down pretty bad in the last couple of weeks. I too barely drive the car pretty much only on weekends and this past weekend I went through about 45 bux in gas.

 

I barely get 200 miles per tank. But I luv the sound of the turbo.......and mash it all the time but I'm in Dallas so the weather is not that cold...