Terrible Winter Gas Mileage!

[colin6919]

I keep track of my fuel usage on all my vehicles and have noticed a HUGE increase in the amount of fuel my Koup is using in the winter. I’ve gone from averaging 9L/100 km’s (~26 MPG) to 16L/100 km’s (~15MPG) in the winter a 58% increase! I understand fuel usage increase in the winter but my previous car’s usage only went up ~10% over normal.
I’m curious if there is a difference in fuel mapping between when the cars engine in cold vs when it is warm, basically is the engine dumping more fuel into the combustion chamber to warm up and causing my poor mileage?

[noodile]

mine doesn't change that much, i still manage to get 32 mpg highway (with cruise control), and around 18-22 city (same as normal).

it has to do with how you normally drive, snow tires = more resistance, if your car is cleaned from snow and ice (affects aerodynamics dramatically), tires properly inflated?.

and how cold is your winter? coldest my koup was in was around 0 F (-18C)

[colin6919]

It can get fairly cold here; easily down into the -40C~-50C range (cold enough to case “square tires”). I’ve checked the tires and there all properly inflated, I do have snow tires on but I wouldn’t expect them to cause such a drastic decrease in mileage. I also make sure the car is clear of snow for both visibility and aerodynamic reasons plus the ice build up on the trunk can stop it from opening. The only thing I can see that might be causing this is I have a relatively short drive to work in the morning (10-15 minutes). My theory is that the engine doesn’t have time to reach its proper operating temperature on the colder days and is using more fuel due to this cold condition. The other possibility I was considering is that it sounds like one of the idler or the tensioner pulley bearings is starting to go bad, this may be causing extra drag and thus returning poor mileage, but again I can't see it causing a 58% decrease.

[win-star]

Mine hasn't changed much, when it's cold, if I drive in city idle for about 1 min and drive right after slowly and it warms up quicker and keeping the engine under 2.5 - 3k RPM

I live 2 miles away from the hwy, if i go on the hwy i warm it up a little longer like 5 mins to properly warm up before going high speed

[SketchedOut]

do you run your car to let it warm up? if so, how long?
much snow or ice there? spinning tires much?

[sje0123]

Warm up time is a fuel consumer. As your car is sitting there warming up you are getting 0mpg. Add that onto more resistance from "thicker" oil and constriction of everything from the cold and you've got a reduction in fuel economy.

[KOUPATROOPA]

My mileage has dropped drastically as well, from 32mpg down to 23-26mpg this winter. Part of my problem is that I moved closer to work but I now live up in the hills and I have a problem keeping my foot out of it while driving on the curvy hilly roads.

[AutoItKing]

My mileage drops every time I install a performance part... intake, exhaust, HFC, etc

[fredycrudas]

My milage drop after i got my solo exhaust muffler, I love the sound and I guess that makes me keep pushing the gas pedal.

[DevilsX]

I floor it harder in the cold cause my CAI screams. Well, screamed

[colin6919]

I found my problem; all four of my brakes wer draging slightly. She's going into the dealership this week to get checked out.

[Donniekl]

Besides the OP's brakes dragging and warm-up time, everyone gets worse economy in the winter months because fuel companies use a winter blend of fuel. These winter blends help keep your fuel lines from freezing, but don't burn as efficient in your engine.

Even if you drove the exact same way year round, you would still get worse mileage in the winter.

[tonyterner]

My mileage has dropped from an average of 28 to an average of 25. I've tried warming it up and not warming it up and get about the same mileage. Haven't changed anything so it must be the cold air. Doesn't really bug me much since I bought the car because its fun to drive not because of the mileage it got.