Gas mileage drop-observations

[Ripsnort]

I know this is a hot topic in many threads but I thought I'd share my observations:

I was average about 22.4 MPG on my normal route for weeks this past summer.
Come fall, I changed my oil, going from what I assumed was 0w-20 to 5w-20 synthetic (It's Mobil oil, and it's cheap at Sam's Club!) Also, during this time, our average temperature went from 65 deg to about 50 deg F.
I assume that more ethanol is also mixed with fuel this time of year? Not sure.

Anyway, I'm now averaging about 20.4 MPG on my normal route.
The factors that changed were A) Temperature B) Oil type C) Possibly more ethanol in the fuel.

That is all!

 

[Crit Rat]

I assume that more ethanol is also mixed with fuel this time of year? Not sure.

C) Possibly more ethanol in the fuel.

It's this.

 

[Ripsnort]

It's this.

I think so too.
I highly doubt going from 0w-20 to 5w-30 would make that much difference...

 

[Foques]

he is not guessing, he's telling you, I think.. and I also think that he's 100% correct.