Winter blend of gas and mpg drop

[drainoil]

Originally Posted by RobertISaar

if they do, it would be the more southern states.... ethanol and cold temps are a bad combo.

IIRC, Alaska has year-round ethanol free fuel because of it.

We have e85 here available here year round. Our "regular" 87 octane has at least 10% ethanol year round. Non-oxy is at select stations only and I've paid almost an extra dollar per gallon (over 87 octane/10% corn) at times for it.

[Mustang Dave]

I notice a difference between Winter and Summer gasoline. I get high 28's - low 29's with Winter gasoline and 30's - 31's with Summer gasoline, even though the Summer blend likely contains more ethanol. Ambient air temperature also makes a difference.

[gone-ot]

...lookup Reid Vapor Pressure (RVP) in this article:

Refining 101: Winter Gasoline

[Mustang Dave]

Yup. The lighter hydrocarbons added to the blend to increase the vapor pressure of cold weather gasoline have less BTUs/gallon.

I've read that in some areas, Summer gasoline gives worse fuel economy due to the oxygenating agents added. (ethanol, etc.) That's definitely not my experience with Safeway gasoline in Flagstaff.

[radioranger]

any body know the effects of adding 2 stroke oil to the gas on an O 2 sensor, seems to really smooth out my truck engine.

[digital rules]

Reviving an old thread, but can't find an answer after quite a bit of sifting. Are the winter & summer RFG's rolled out nationwide, or is it mainly in higher pollution metro areas? I saw this EPA paper & not sure if it applies or are these even cleaner boutique formulations for certain areas?

[Hersbird]

Originally Posted by RobertISaar

if they do, it would be the more southern states.... ethanol and cold temps are a bad combo.

IIRC, Alaska has year-round ethanol free fuel because of it.

I realize this is an old thread but that is not why Alaska doesn't have to use Ethanol. Their senators lobbied and got an exemption (probably a trade for a vote somewhere else) because it costs a bunch more to move gas from Kansas up there where they are already swimming in domestically produced gas. The big argument for Ethanol was to increase the percentage of domestically produced fuel. Ethanol works just fine in the cold places of the world.

So from what I read the winter blends do have a tiny effect on economy, but the mileage hit most people see is from the cold temperature of nature, not from the fuel they use. The biggest hit is from the increased viscosity of oils and the longer enriched warm up times of the engine.