Cold wx fuel economy

it's -20C and colder right now. I'm getting about 15L/100km or roughly 15mpg.

In the summer I was getting 11-12L/100km which was significantly better.

My Tacoma has 5000km on it if that matters at all.

Is this normal?

 

I was wondering the same thing. Was 40 degrees on Thursday was getting 18 mpg, dropped to 27 degrees now and Im getting 15 mpg.

 

Pretty normal for any vehicle to lose 10% - 20% fuel economy in the winter. Winter fuel blends have less energy. Cold air is denser and creates more drag. Oil in the gear boxes is cold and stiff. Extra warm up time before the engine gets to the efficient operating temp. Plus any snow that you might have to drive through creates more rolling resistance.

 

Denser air needs more fuel to hit target AFR but also makes more power so theoretically would take less throttle but if you don't change your right foot habits, real world results usually means lower mpg.

On top of what's already been said about warmup, drag and rolling resistance.

 

Thanks for all the replies, I had suspected this but thanks for clarifying.

 

Colder air = thicker air. More fuel required to maintain ratio of fuel to air mix. What he said above

 

I let my engine warm up a few minutes at idle before driving once temps drop below zero. Doing that every time adds up to a decent amount of gas burnt sitting still.

 

Same for me. 19-20 in summer and 16-17 now. Driving a lot in 4x4 and pushing snow around is what I attributed the decrease to.

 

I was getting 18-20 mpg during warm weather. With the winter blend fuel and colder temperatures, I am averaging 16-17 mpg.

 

Lots of people want to blame it all on "winter blend gas" but that only explains about 2% less, but might be up to 5% if your summer gas is E0 and winter is E10.

A few more things not mentioned.

Lower tire pressure if you aren't diligent about airing up in the cold.

Cold tires have higher rolling resistance.

 

Well, it's -10ºF here, about -23ºc and I got 14 MPG on my drive home last night. It's usually around 17 so yep it'll drop. I got 12 earlier getting to my parents house in 4wd through some snow. Tis the season!

On the bright side, the defroster seems to work pretty well and it will warm up from below freezing to almost full operating temp (on the temp gauge anyway) in 2-3 miles so that's a plus. I know all the gears and other lubricants probably won't be totally warm that quickly but still. I also lost 7 PSI in my tires from the temp change. It was in the 30º-40ºs when I left town, came back yesterday to negative temps and low tire warnings.

Drives great in snow, at least the KO2 bro tires seem to do the job decently. Never had an issue with the originals on my Tundra and it went though a foot from time to time.

 

completely normal. I get 23 combined city/hwy per tank and now I get 19. Same driving habits, same routes.

Colder air is ruthless, truck runs rich, air is thicker, tire pressure drops, everything about winter sucks. oh and the winter blend fuel is crap.

 

Sounds stupid but check your tire pressures. Being Canadian I always find it drops quickly when the temp tanks like that. I set mine about 32 / 33 all around and when the roads are snow covered etc they warm up to 34-36. It will help. Just check them when you start driving to see where they are cold, you maybe surprised.

 

Yes, I'm going to do that. All 4 tires are reading 27 PSI which is low and the cold wx is to blame. I would assume that would attribute to the reduced fuel economy.

It has warmed up to around freezing and already I'm noticing better numbers.

 

The weather warmed up 20 degrees on the average. With the same fuel, same tire pressure and same driving habits, my gas mileage increased 2.0 mpg.