Engineering question - car engines...

[SpokaneCY]

There's a very specific point both in the fall and in the spring where my gas mileage takes a giant leap forward. I know every engine will be different, locations, altitudes, etc. but is there a generic sweet spot for temperature where internal combustion engines operate best?

Or is it simply I'm not running my heater or AC during the shoulder seasons thus getting the mileage boost?

 

[mywayorcyway]

You get an increase at both times? Not one goes up, other goes down?

 

[illinoiscyclone]

It's because of daylight savings time.




Disclaimer: I'm not actually an engineer

 

[Dopey]

Increases greatly 2 times per year? Has your mpg crossed into the 4 digits yet?

 

[Acylum]

Theoretically, you should get better mileage with winter blend fuels I believe. But then that advantage is lost due to colder temps. The jump in the spring could be explained by still buying winter blend fuel as temps increase. This is a total shot in the dark.

 

[ruflosn]

Do you quit letting your wife drive the vehicle during this time?

 

[Cyclonesrule91]

I would guess your mileage goes up in late summer early fall and late spring early summer. In the Winter there is a lot more warming up your car before you drive and also while warming up the computers make your engines run richer fuel/air mixture and both cut into your mileage. When it's warm you always have your air conditioner on I assume and that draws power cutting into your mileage as well.