Winter Gas vs. Summer Gas

[excelguru]

In the past, people have moaned and wailed about this thing called winter gas. Until now, I've never owned a car that made enough HP to really care about the difference. But now, things are different...

What is the real difference between winter and summer gas?

Why do the fuel companies change it to begin with?

What are the effects on my car and it's performance?

What can I do about it?

Keith

[Chaplin]

Keith-
I think the additive is called MTBE (I can't remember what that stands for), somebody correct me if I'm wrong.

The effect of the additive is to oxygenate the gas. It is designed to reduce emissions. The only true effect is that I am aware of is that gas mileage is reduced apx. 15%, power is reduced and I know a lot of gas station attendants complain of headaches and nausea when they are forced to switch to winter gas.

I don't know there is much you can do about it, other than stock pile a couple hundred gallons of summer gas (But the way those 2 4's suck gas, that probably won't be enough for you to make it through the winter anyway )

I didn't think that they put that stuff in the gas down by you- I thought it was only a Northeast or cold climate thing. If you look on gas pumps by you there should be a label which says that the gas is oxygenated or that it contains MTBE (or whatever the correct name is).

[teamfour]

Interesting topic. I use Sunoco 100 Unleaded race fuel because it is oxygenated. I can believe the claim of lower mpg, but how can oxygenation hurt power when one of the most respected names in racing fuel does it on purpose?

[Ron61]

Chaplin,

California has MTBE in their gas and it is really bad. It does all the things you stated plus it pollutes the water and is poisionus. ( spelled wrong ). Our Emperor and the Governor of Nevada had a deal a few years ago to get rid of it and Nevada did but Emperor Davis took several million from the oil companies so they didn't have to get rid of it. I don't think Nevada will allow anyone from Calif. to bring a boat into the state with gas in it now. I know one person who was going to Lake Mead and he had his boat full of Calif. gas. They stopped him and he got a large fine, plus they took the boat to a safe disposal place to have that gas removed and he had to pay for that. Several wells and lakes in Calif. are polluted by that crap but it just costs to mcuh to make them stop putting it in the gas.

Ron

[teamfour]

FWIW, the Sunoco 100 GT fuel I referred to has an oxygen rating of 2.7 measured as Wt. %. I'm not sure how this compares to the winter gas.

[flipper35]

The volitility (sp?) is different. The additives are there year round.

[Hal Copple]

I can tell precisely when Upstate SC begins the "winter gas" in the fall, and when i get my first fill of "summer gas" in the spring, where i live, about early April. Winter gas has a higher Reid Vapor pressure, for easier starting in older, carb cars.

But on my car, it only makes for carb percolation and boil over, and hard starting on a re-start if my engine has sat for over about 15 minutes, or enough to boil all the gas out of the carb. Even with a heat shield and a half inch phenolic spacer. If my car is sitting in warm temps, in traffic for an extended time, with the winter gas, it will boil over, and flood-my engine, so i have to race my motor just to burn it out, and get new cooler gas into the carb.

I don't think it carried less heat energy, but it sure can make a hot carburated V8 a bit of a trick to run in traffic on a relatively warm winter day.

On the other hand, it does make for lots of attention getting throttle blips!

[Gordon Claunch]

The difference in winter and summer gas is the vapor pressure, you can use less light ends in the summer time, We no longer use MTBE{methyltertiarybutalether} at any Shell California Refineries, we are now making carb3 gasoline and yep it cost more, if a California refinery is down for maintainance or problems the price will go up, because you can't get it from anywhere else, you can't bring it in from outta state, if that makes you unhappy, kick a Democratic enviromentalist in the nuts!!!

[flipper35]

Gordon, I tried to kick the coin-op gov, but my leg doesn't reach. Can I do that pass it on game from when we were kids? And what is carb3?

[Ron61]

Gordon,

A question. Is Shell the only company in Calif. that is not using MTBE now ? The reason that I ask is the Texaco, Chevron, and other gas pumps in this area still have the MTBE warning on them. I have found one good use for this gas. Throw it on a fire and it puts the fire out. And the stink at the pumps when filling up is bad.

Thanks,

Ron

[Gordon Claunch]

Flipper35, Carb3 is the 3rd phase of California air resourses board required fuel blends for air pollution, California has the cleanest gas there is, that is why you can't import from say the gulf coast during turnarounds for maintainance and such, remember the diesel stuff of about 5-6 years ago, that was carb2, they spent millions refitting the refineries and the same now with new units, think about a bottle of water for $2.00, it goes through a simple filter or carbon drum and no one complains, a barrell of oil has to go through at least 4-5 units, heat ,catalyst all kinds of stuff for a $1.75 per gallon, I hate paying too but it really is very cheap!!

Ron 61..Arco does not use MTBE either, it all depends on where it comes from, here in Bakersfield, We send our gas from Lancaster/palmdale area up to around modesto to the central coast and eastern California, we are a Shell refinery but if you buy gas at any station it is ours!! All Manufacturers have their additives at the loading rack and the drivers add it in when they load

[flipper35]

Gordon, I didn't want to kick him for gas prices, I just don't like him. How come we only get 91 octane here when it is 93 octane back home. my car runs fine on 91, I was just curious. They are growing lots of sugar cane here for the companies switching to an alcohol based additive. I am glad my car has newer seals in the fuel system.

[Mr.Fixit]

The oxegenate as I understand it (i never got better than C's in organic chem, so don't take this as if I was a fuel chemist) adds oxegen to the fuel to promote more complete combustion. This makes the fuel allready have some "air" in it, so you gotta dump more gas in to deal with the airflow you motor can inhale. So you gotta jet a wee bit richer because the changed stoichiometry of the fuel itself. Your motor will inhale a known CFM of air, you have to dispense enough fuel for this air. The oxygenated fuel allready has some air in it, so you gotta dump more fuel in to make up for that, since you are still inhaling the same CFM of air to begin with. Methyl-tertiary-butyl-ether is poisoning our water here in california, they keep finding it in wells and you can't get it out.

[Gordon Claunch]

Brent, This a complicated issue, but here goes, in California if you blend 92 octane or over, unless you have very expensive advanced control systems or a Fluidized catalytic cracker
{ A refinery unit} Which alot of California refineries do not have, you have to follow a patent formula owned buy Unocal{union oil}and therefore have to pay them a royalty on every gallon of gas without the controls or units above it was seat of your pants blending, unless you followed unocals "recipe" for distillation you could have very costly reblends, so to avoid this the distillation numbers were changed, a 50% of 210° was Unocals recipe, by changing to a 50% at 210.5, which rounds up to 211 you avoid the costly patent, but you make 91 octane, as usual it is all $$$$ and cents!!!

[Todd Hedges]

Winter Gas = Gashole lodging at a ski area - Lake Taho NV.
Summer Gas = Gashole road trip with lodging in Baja CA.

[Carroll DeWeese]

Virtually no one around here drives their Cobra in the winter. We do not have to worry about the difference in gas for our Cobras, just for our daily drivers.