accord___2000

So why is that my gas mileage always goes down in winter?
I heard something about different fuel mix, any other reasons?
And anybody knows what is that different fuel mix means?

cautrell05

Im not sure about fuel blend but most of it is the tempature. When the engine is cold it requires a richer fuel mixture to operate. When its colder out side it takes longer for the engine to warm up. Im also pretty sure that the air temp has something to do with it but Im not 100% certain on that.
Nick

TheMuffinMan

iTrader: (1)

colder air

Perfectionist

Everyhing that moves moves a little stiffer when cold, too.

Regarding the fuel blends... Some geographic areas receive a "winter" blend fuel during the cold months. It's blended to evaporate a bit more readily and aid cold weather performance. I suppose you could google for the exact information about it.

Trumpster

Colder air = more dense = higher fuel consumption to make a stoichiometric mix....I believe the golden number is 14.2:1 (that's 14 "parts" air to 1 "part" gas). I've always wondered about the "winter mix" of gas....I'll have to look more into that myself

street_accord94

stoich is 14.7:1 and vehicles will typically run richer than that.

interesting read on oxygenated fuels ("winter mix")
http://www.epa.gov/oms/regs/fuels/ostp-3.pdf