I can't seem to find any info that really seems to address my question. But I haven't averaged lower than 29 mpg since I bought my fit base auto new and in the Smoky Mountains through Kentucky the steepest section on 75 I averaged 37 mpg and the overall for the trip from Johnson City Tennessee to Michigan I averaged a total of 39 mpg's with the fit loaded with junk because I was moving. I did the actual math and ignored the Honda's mpg computer. However now that I'm living in Michigan on the flat roads I can't seem to get better than 31-34 on the highway. Any ideas of the reasons? The gas quality in Michigan different than in the south? Or could it get better after my first oil change? I'm thinking there is quite a lot of wind around where I live now and that may affect the fit as well. Any insights would be greatly appreaciated.

 

It's really cold and fuel economy goes down when it's cold. Also the seasonal fuel formula changes.

 

I think the cold temps are the culprit.

 

With the subzero temperature here in Chicago, I'm averaging 26mpg vs. in the summer, I averaged close to 32mpg doing same route.

 

Is it just b/c of warming up or a combination different gas mixture like noted above? What is the need for changing gas mixtures in winter? Freezing? Sorry, not a area I have ever dealt with before.

Thanks for the awesome help.. I love this site!

jtcannonball

 

I noticed my MPG has gone down by 1.5 over the last couple of months. The only thing that's changed is that it's gotten COLD! And I live in GA, so it must be much colder where you are. If it goes back up in the spring/summer, I'll know for sure that's what it is.

 

the distance of your routes can make a huge difference -

I used to get no better than 26 mpg on every tank when my commute to work was about 8 minutes.

I moved a few miles further from my job, and now my commute is about 12 minutes. Now my average mpg is always 32 without fail - a whopping 23% improvement!

Also, gas additives/blends are different in different areas, I think. I read something about the percentage of ethanol greatly affecting mpg, with some blends using 5% ethanol and others using 10%. Not sure - it's hard to find info on that.

 

Gas quality has a lot to do with mpg, living near Detroit you probably have reformulated Gas which has less BTU's than it the south. Cold air is dense so more fuel is required and thats worth about 25 percent less mpg. This should explain the fuel injection Wapedia - Wiki: Fuel injection and this the ecu Wapedia - Wiki: Engine control unit . I got 32-35 mpg in my fit in the winter and my new civic I am getting 30-33 so far but its colder than normal right now so as it warms up next week it should go up. They might be putting E15 in the gas but it should be labeled, but until they're caught they will try to get away with it. E15 (a blend of gasoline and ethanol) | Fuels & Fuel Additives | US EPA

 

I've traveled through New York State several times, but I don't fill up there any more. Every time I did my range was shaved by something on the order of 100 kms per tank.

As for short (ie: 8-minute) to-and-from work commutes, your engine barely reaches operating temps. And cold engines get drastically fewer miles per gallon than warm ones do.