Well the cold has come here in TX (in the span of a few hours no less) and my mileage has taken a hit (down to 12.4 from and average of 14.5).

Maybe it was just this one reading, dunno.

But I think I remember seeing here that its normal to lose a little bit in the cold?

If so, what causes this?

 

Much denser air = adding fuel?

All I know is I love the way it runs on this weather!!

Although, I haven't noticed any drop in MPG yet. We're hitting the road for a short road trip this weekend so maybe I'll see then....IF it cools back down like it's supposed to.

 

After tracking mileage for the past five years, I always notice a 1.5 mpg decrease in winter months (or a 1.5 increase in summer months, however you want to look at it.)

 

I've got to agree with FamilyRide on this one. I see a little better mileage in the summer months here in VA, but man does this thing run better in cool weather!!!!! It seems like the computer can't quite get the timing offset right in hot weather---definitely NOT a problem right now.

up to about 70^F great power
70-85^F OK
85 and up with VA humidity---well we won't talk about the negatives right now

Sidewinder

 

Hi , I 'm up here in Canada , a 2-2.5mpg loss is normal in the winter time at about 0'F ;but you get more hp and as long as the heater keeps your butt warm who cares.
Most of the gas is wasted in the first ten minutes while your eng.
is warming up the rest is the loss due to the fact that rear end
fluid and grease has turned to sludge.

 

http://www.synthetic-oil-online.com/articles30.htm

This site has a paragraph that says a bit of a mpg drop during cold temperatures is normal...

 

Ok thanks

I havent noticed a great deal of increase in power...but I have a Windsor so I have the knocking when I start it up on cold days.

 

Oh yeah bigtime . . . depending of course on what you are considering cold. Up here in central British Columbia, I notice a small drop (maybe 10-15%) when it drops to -10C or so but when it gets down to -25C or colder, my mileage is TERRIBLE. Probably drops 30%-40% from summer mileage.

The neat thing about it being that cold is the amount of condensation coming from the exhaust when you punch it . . . damn thing looks like a vapor trail

 

Well, we're lucky if we stay at freezing temps, I dont think Ive ever seen it below 20 here.

Our old suburban had a GIANT condensation trail coming from behind it while the engine was still cold. I would be staring out the window until the trail quit coming out when we went to school.

 

I think the main culprit is winter blend gas. My mileages is down 2 to 3 mpg in winter and I use Mobil 1 0W30.

 

Tiger - that is often what gets blamed, but with colder temps comes lower fuel mileage, period. There is little to no change in our gas year around (10% ethanol, year around), and my mpgs are about 2.5 mpg less in december than my average (and about 2mpg higher than average in summer).

 

I would say that as the air gets colder the air/fuel mixute gets denser and the drive train absorbs more energy. At some point the energy absorbed by the drive train increases at a faster rate and can't be made up by dense air.

You see it best when you run in 4H when the temp is close to 0F. The engine roars and works hard and you're not realy going anywhere.

Even the engine oil runs cooler in winter. Someone reported that the engine oil temp is 100* hotter than the outside air. There is a min temp it will go to on cold days though.

 

Yeah when it's colder it definitely hits higher RPMs unitl it warms up.

My MPG is still fluctuation though (and our temps here have been going up and down so it's hard to say right now...)

 

So in short it appears that we have multiple factors to look at as to why are MPG is decreasing in the cold weather. I will sum up as many as I can think of that have been previously mentioned and a few that haven't

1. Dense Air causing increased fuel from timing compensation
2. Lead foot syndrome from realizing said increase in power
3. Longer warm up times
4. Lead foot syndrome
5. Colder lubrication fluids causing more drivetrain loss
6. Lead foot syndrome
7. Dense air equals more air resistance on chasis at hwy speed
8. Lead foot syndrome

I think I found my problem!

It's gotta be the dense air, notice that was mentioned twice

 

I have noticed I have to give it more gas when going down the freeway sometimes. I try to stay out of it when I can, but sometimes I have to give it more gas or I just slow down.