winter gas vs summer gas

Cheekster96 · April 12, 2006

Hey all. I have read from different places that "winter" gas is different (blend) than summer gas.

What is so different?

I do know, that the truck i had, got close to 21 mpg overall (95% highway). Winter months came and the number dropped to 16 (same driving habits).

What, if anything, are the differences between the two blends?

I run either Shell or Mobil/Exon.

Lee

Butch 02 Denali · April 12, 2006

The major difference is anti-knock is reduced and anti-freeze is added in the winter.

pwall · April 12, 2006

Let's no forget the cost...in the winter, it's more expensive because of the additives to prevent freezing, and in the summer it's more expensive because it's hotter and the sun is shining..whatever excuse they can use to raise the price.

Cheekster96 · April 12, 2006

Well, i dont know why or for what reasons gas companies jack their prices up. I paid 2.47 not too long ago, and withing two weeks, the price now is 2.69 at Shell.

We hit 60F today with lots of sun, havent been out of the house since this morning, i bet that Shell station raised it's prices even higher....

oh well..

later

Lee

Frozen001 · April 12, 2006

Last I heard... oil companies are blaming the higher prices because supply is down due to the change over from winter mix to summer mix. Like someone else said... they will say anything to get the price higher....

SilveradoWV · April 12, 2006

Yeah I was going to say about 75 cents per gallon is the difference but looks like you guys had the same answer!

Cheekster96 · April 12, 2006

If their are additives added to keep the gas from freezing, how does it manage to get fewer miles to the gallon?

does the performance of the engine falter with the winter gas?

hope they change over back to the summer blend soon.

Lee

Raptor660r · April 12, 2006

You also let your truck warm up longer (atleast I do) in the winter. My old truck would run for about 20 mins before I went out to get in and drive.

Cheekster96 · April 12, 2006

If it is really cold out (like sub zero F temps), then i usually let it run for about five or ten mins max. Just drive off easily.

Takes me about five mins of driving before i get to the turnpike, and soon thereafter, the truck is warm. There has been a few times ( i travel 10 miles on the turnpike to work) where by the time i got to work, the heater was just blowing hot air.

Never noticed a difference between the different blends of gas though. Other then the mileage decrease.

Lee

Tucson_02Silverado · April 13, 2006

It's not just winter/summer. It's all throughout the year.

The oxygenated blends (MTBE, methanol and "crap") is created for different regions and different times of the year.

Every blend change requires the refineries to shut down.

Cost of refineries shut down/startup.

Cost of different blend agents.

etc.

With OBDII and just about every gas engine produced today having at least and LEV (low emissions vehicle rating), this fuel blend idea is another where whomever thought it up should be shot.

FWIW, the 5.3L is rated ULEV (Ultra Low Emissions Vehicle). Some of the Honda's, Toyota's and the like have ULEV II ratings.

dewfpo · April 13, 2006

Besides the oxygenates in the winter blended fuels for some areas (read less fuel mileage).....winter fuel differs PRIMARILY from summer fuel by having different Reid Vapor Pressure (RVP). That is, summer fuel doesn't need to vaporize as easily as winter fuel. The reason for this is temperature. In the summertime, with all the ambient heat available if the gasoline vaporized too easily, there would be vapor lock and carb'd engines would have a hard time starting, etc.... In the winter, you want it to vaporize more easily in the cold weather so that it will start when it's cold.

DEWFPO