Where I live the temperature was -18 two weeks ago and 56 today. I don't winterize my bike, if it gets above about 40, I try to get out at least every couple of weeks and put on about 100 miles. Warm everything up and fill with some fresh fuel. Here is my question, my mileage has dropped from about 41 mpg to about 38 mpg. Anybody else have the same thing and is it because the engine never gets as warm as it should, to be the most "efficient"?

 

I don't ride when it's -18 or anything. Really, I don't ride when it's below 20, and usually it's got to be at least in the mid to upper 40's before my smile thaws out for a bit.

I always get worse mileage in the cold.

I just figured it's because the cold air is so much more dense, and the computer dumps more fuel in, to keep the ratios in line.

 

I'm just guessing, but perhaps the winter formula of gas is the reason???

I don't know what they change, but they do change fuel formulas for winter and summer.

 

Winter formula plus gas mileage is worse in cold weather.

http://www.swri.org/10light/mile.htm "With this in mind, hot air is less dense than cold air; therefore, the engine breathes less hot air per revolution and requires less fuel."

 

Yep, I've noticed it myself. I think it's even worse with the ethanol blends.

 

Dense cold air = more drag. I lost 3 to 5 mpg .

 

Even my truck uses more fuel in the winter. Partly because the enrichener is engaged longer till it gets up to operating temp. And that may be a couple miles down the highway. It will hold the trany out of overdrive till the trany reaches 72 deg. Everything works a little harder in the cold. Oil is thicker, different gas formulation. Winter just sucks in general.

 

I have noticed a drop of 2 to 3 MPG here

 

I don't ride below 70 so I can't help here.

 

Happens every year, probably multiple causes but you can set your watch by it.