I picked up my 2016 Fit 6MT in Nov 2015, only drive in the city, and not very much. At that time I was getting about 7.0L/100km 33.6mpg. In the winter with snow tires on in Feb 2016 I was getting about 8.2 L/100km 28.69mpg. The snow tires came off in May.

Recently with the better weather It seems like I am now averaging 6.2L/100km 37.94mpg. I am still a consistent driver, glide down hills, anticipate traffic lights, no jack rabbit starts, but my driving style over the past 7 months has not changed much.

I have heard that there is winter and summer gas here in Canada, but could there be some other reason for the improved fuel economy? I did not think I could approach 40mpg while driving around the city.

Fuelly

 

I've noticed the same thing. Winter blended fuel has less thermal energy than summer blended fuel so there's that effect. Then too, you said you ran snow tires during the winter, and they have much more rolling resistance than summer/all season tires.

 

In addition to seasonal fuel blend changes...there's the simple temperature factor.

A cold engine requires a lot of additional fuel to run.
The colder it is, the more fuel needed.
Long warmup times equate to lots of extra fuel burned, therefore lower economy numbers.

When it's warm outside, it doesn't take nearly as long for an engine to reach normal operating temp, warmup time and therefore consumption is reduced.



Snow tires can reduce mileage too.

 

Here's a graph of my mileage (Imperial MPG vs Fillups) over 9 years with my 07 FIT. It's pretty easy to pick out the seasonal trend. Temperature has a huge effect (you really notice when you get a very warm week during the winter). Snowtires also cost 10% or more. I'm in NS by the way and drive a consistent route.

 

One more thing is use of the car. In my case, I seem to get the poorest mileage driving to and from work. It's only five miles, uphill one way, and barely long enough in cold weather to get the car warmed up.


During the coldest part of winter, I tend to "hole up" at home, so, basically, I drive to work and home again. That's it. When warm weather comes, I tend to do more "distance" driving due to better weather and road conditions. The extended highway trips raises my overall fuel economy (even though I'm driving more, and using more fuel).