Temperature Drop affecting MPG

[Ludercrz]

So driving the same way I have been driving, I used to get ~6.8L/100km (~34mpg)

as of this week the Temperature dropped to near freezing and my average MPG after this last fuel up earlier this week has been 8.8L/100km (26mpg).

I know the fact that I have the heater on doesn't help the engine but that's kind of sad. I wonder how much worse it will get once it goes way below freezing in the snow and stuff.

[silverbullet]

I do not like cold weather, I see about a 20 percent average drop in mpg. I can say that the higher loads is one problem as seen on by the higher engine loads and the enrichment in the fuel trims.

Hondata in the flashpro help has some info on this. When the engine temps are below a certain level more fuel is added to help keep the motor run as it warms up. Colder intake also adds fuel to the trim. Air is also denser so more fuel in needed compared to summer. Longer warm ups needed to clear snow and ice adds 0 to the average for every minute not driving.

If you think about all the different things that can hurt mpg in the winter 20 percent is not bad. Gas use to be cheaper so it was not a big deal but they make their money in the winter by us using more.

[gomarlins3]

Yes, colder weather will drop your MPG. In my original Insight, we would block the radiator and some of those guys would run a hose to their cat to get warmer air into the intake.

[Scotty001]

Yep - a combo of the winter fuel mix and temp will mess with your MPG..

[Ichii]

Yea I notice the drop in mpg, usually I get about 45-46mpg, but yesterday I got 41-42.

[gordonfc]

A internal combustion engine uses 14.7 lbs of air to 1 pound of fuel for maximum efficient.

As temp. drops air condenses in volume i.e. cubic foot increases in weight per cu. ft. requiring more gasoline.

Temp. rises oposite is true, air volume i.e. cu. ft. expands weight of air per volume decreases requiring less gasoline input.


I flew piston, turbo-prop and jet aircraft for almost 40 years.
At normal cruising altitude for a Learjet 25, 41,000 ft, the air temp is always about -56 degrees F.

But the air is also way thinner up there so we burn as much fuel cruising at 500 mph as we do idling on the ground in summer.

[Klasse Act]

A couple weeks ago, when it was in the upper 60's to 70's I got my best mixed driving mileage to date, 44.2 mpg but since the temp has dropped, I've gotten 41 mpg, yesterday infact netted me 41.3 mpg. I run a drop-in K&N and run premium fuel too.

[Lankysean]

I wish I pulled that kind of milage, I get about 36mpg but my ride to work is the worst ride possible for milage. It's 3 miles in the city and another 3 miles on the highway with traffic lights. I will say the 36mpg I get now is a HUGE improvement over the 19mpg I got in my chevy cobalt.

[rjjensen]

yep its the winter fuel mix...terrible.

[silverbullet]

Originally Posted by gordonfc

A internal combustion engine uses 14.7 lbs of air to 1 pound of fuel for maximum efficient.

As temp. drops air condenses in volume i.e. cubic foot increases in weight per cu. ft. requiring more gasoline.

Temp. rises oposite is true, air volume i.e. cu. ft. expands weight of air per volume decreases requiring less gasoline input.


I flew piston, turbo-prop and jet aircraft for almost 40 years.
At normal cruising altitude for a Learjet 25, 41,000 ft, the air temp is always about -56 degrees F.

But the air is also way thinner up there so we burn as much fuel cruising at 500 mph as we do idling on the ground in summer.

+1, that is why synthetics were made.