Is it colder winter temps? Are you letting it idle to warm up? And does your driving involve short trips with stops before thr car reaches full operating temp? ..these are in town/city mileage killers.
I also see a similar drop in winter anywhere from 10-20%.
1) From colder temperatures there's more friction and takes longer to warm everything up. Colder air is denser, so more air drag too (more noticeable at hwy speeds). 2-5%
2) You've got winter-gas, with more ethanol, so less energy. 1-2%
3) You're likely having the blower on windshield setting which automatically engages the A/C in the Fit, so another hit to mileage. 3-5%
4) Most people suck at checking tire pressure regularly when it's nice outside...in the winter most people never even do it. When was the last time you checked them? And if you check them in a garage where it's warmer and they are good, when you go outside to below freezing, the PSI can drop below ideal pressure, so higher tire friction. 1-10%
5) Canadian Winter = shorter trips. If in the summer time you will walk 15 minutes to the store or whatever, in the winter time you will take your car for that short drive and get awful mileage with the cold engine. Also summer time you likely take longer hwy road trips vs winter time mostly city. 1-10%
6) And what oil do you use, 0W-20 synthetic ? 1-3% if using dino oil or wrong viscosity.
Last edited by Andrei_ierdnA; 01-28-2017 at 12:45 AM.