jcman

We sure talk allot about the oil we use to the point that a petroleum chemist could write a book.

So what about the different "brands" of gasoline, after reading the last oil thread and the contributing posts a few interesting comments were made about the effects of gasoline on oil.



Can we take a stab on this $4+ a gallon necessity?

2.7Lturbo

heres the dirty little secret, other then octane ratings, all gas consumer grade gas is essentially the same minus certain brands that add stuff (techron etc). hell most of it comes from the same refinery and then is just loaded into different comanies trucks!

jcman

Thats what I've heard too, but I'm wondering about Shell without the ethylene if thats true?

BTW, good to hear from you dude.

eejimm

Disclosure - several close friends used to work for an oil company, and I've picked their brains to get the following:

All gas is blended from several components, including (nowadays) ethanol (which can be a problem with some types of rubber on older vehicles.). This blending is generally done at the closest refinery or a local distribution center (shipping gas in a truck is way more expensive than in the pipelines between refineries.)

You're right, basically gas is gas, with a certain octane rating based on its chemical composition. Although gas is also blended differently in different parts of the country, at different times of the year. Florida summer gas is very different from winter Minnesota gas, even if it's all from Shell.

Different companies / stations order certain additives (a-la Techron) that is added to make the formulation "theirs". That's why in most areas there are some independent stations which always seem to have the cheapest gas - the additives can be very expensive, and the low-cost stations have the option to order their gas with little or no additives.

Without the additives, the gas can have lots of unwanted side-effects - varnish buildup, water absorbtion which can lead to rust in the gas tank and erosion of injector nozzles, etc. You'll probably never find out the truth about what the additives do (is Shell's additive really better than Total's?) since they're very proprietary about it - what else do they have to "sell" you on?

Best I've found to do is find a brand name gas that your car likes in your area - high octane is worth the extra few cents for our cars, IMHO - based on trying several tanks of a few different companies, and if you notice a difference, stick with the one that works best for you. If you don't see any difference, buy the least expensive of them.
Jim

2.7Lturbo

Basically everything he said!

Disclosure - whole family lives and works in Huston

Just Me

yes, the only difference is the additive package. But stop right there. The additive package is very important!

G

xradman

I try to use the following gas preferentially in order (all at the highest Octane available, usually 93)

1. Chevron
2. Shell
3. Texaco
4. Exxon/Mobil
5. Sunoco
6. Other name brands

There's no Chevron station near home or work, so I usually fill up with Shell, Exxon, or Sunoco most of the time.

RMsALFA

Location-location-location.

Gasoline is vastly different in certain parts of the country and can effect performance and mileage drastically.

"Big city gas", where there is a real or EPA-perceived "smog" problem is a real mileage killer. For years, I've checked and re verified and the answer is ALWAYS the same. Gasoline in the CHICAGO area has approx 10% less energy per volume then gasoline from northern WI. You will typically get 10% POORER fuel mileage out of big-city RFG (reformulated gasoline).

http://www.epa.gov/otaq/fuels/gasoli.../rfg/index.htm

Since Chicago was also one of the first areas to run ethanol-blends (which also subtract from your overall mileage), we poor citizens have been struggling for years - not getting the energy other parts of the country get when we fuel our tanks

Cities like Denver also get their mix worked on to compensate for the altitude, although I don;t know what, if any, effect that has on mileage.

I'm always amazed the poor performance of RFG isn't on the radar screens of city dwellers. Maybe they don;t know they're paying more-for-less ?

xradman

Winter gas together with mandatory 10% Ethanol blend is really a mileage killer. However, since that's all that's available in my area, there's nothing that can be done.

SloopJohnB@mac.com

Anything on the TopTier list.