decrease in mileage

[mr9865]

Originally Posted by Conor

At the petrol station (as you call "the pump"), there are four choices.

1. 95 unleaded
2. 98 unleaded
3. Diesel (which is excellent for economy, and very popular)
4. LPG (liquid petroleum gas)

The choices stay the same whether it is winter or summer, the higher octane fuels work just as well in summer as in winter.

What we do is choose different oils mate, depending on what climate you come from, as the temps in the EU vary wildly. -38C in Poland in January, but this winter was unusually harsh for everyone.

Diesel is the best choice, and I heard it has a bad rap in the USA, but we don't use agricultural fuel in diesel cars, in fact, it will destroy the engines.

Diesel gets 80mpg in modern vehicles. Don't think they sell in the USA though. Not sure.... google BMW efficient dynamics for a good example.

I don't know if this will help but in Wisconsin the octane stays the same (87 89 91 93) just the blend changes during the winter.

[b_hickman11]

Originally Posted by Conor

At the petrol station (as you call "the pump"), there are four choices.

1. 95 unleaded
2. 98 unleaded
3. Diesel (which is excellent for economy, and very popular)
4. LPG (liquid petroleum gas)

The choices stay the same whether it is winter or summer, the higher octane fuels work just as well in summer as in winter.

:

This is the same for the states except for the we dont have LPG at most stations and the octane level is a little lower. What I am saying is though even though the pump still says "89" or "95" octane, in the states the gas is different in the winter and the summer. We have winter gas that is 89 and summer gas that is 89 but they are not manufactured the same way.

[Yaris Hilton]

The octane numbers stay the same in the U.S. as well. What changes is that in the winter, refiners use more of the light, volatile butane and pentane hydrocarbons in gasoline. In the summer, those vaporize too easily and can cause vapor locking of fuel lines, so they're pretty much left out with heavier, less volatile hydrocarbons used. Those don't evaporate well enough in cold weather for cold engines to start easily. The heavier hydrocarbons have more energy per gallon than the light ones.

[eht13]

^ Exactly. To the average consumer, the change from winter to summer is transparent... they have the same octane selection to choose from year-round.