Winter Gas

[RUFFSTUFF]

Thought this was interesting...

http://zhome.com/ZCMnL/PICS/winterGas/winterGas.html

[Yaris Hilton]

MTBE's been pretty much extinct in the U.S. since 1996, but the general points of the article are right on. When the weather's cold, more volatile fuel helps engines start more easily and run better. Main way vapor pressure's increased is by adding more butanes and pentanes in the winter. They won't work well in the summer, as they vaporize too fast. If you'll notice when you open the gas cap to refill when we have warm, summery weather on certain days after the switchover to winter gas, you get a big WHOOSH! from the high vapor pressure in the tank. That means lost fuel. But save a couple of big cans of summer gas and fill your tank in the winter and see how you like it. It'll be harder to start and driveability may suffer during warmup. Plus, the butanes and pentanes are cheaper than other constituents of gasoline, which is a reason gas prices go down in the winter.

[RUFFSTUFF]

Yeah, I guess ETBE is the stuff now...

[RedRide]

Yeah , MTBE has be banned for a while due to it's cancer causing properties.
The article seems dated.

One of the sutituutes is alcohol which is now added year round to many brands.

[Yaris Hilton]

The main reason MTBE went out is that it's extremely persistent and foul tasting in ground water. Got in lots of ground water from leaking underground gas tanks. Also in lakes and rivers (where it got in due to use in boat motors) from which many towns drew their water supplies. Most people can taste a few parts per million, and don't like it.

[why?]

Yeah , MTBE has be banned for a while due to it's cancer causing properties.
The article seems dated.

One of the sutituutes is alcohol which is now added year round to many brands.

adding ethanol to gas is a federal mandate, not a choice.