Drifting

Can you guys enlighten me on if there are any real differences in gas between the major gas companies?

I was told that there is something in gas from Shell and other gas stations owned by Shell that creates more soot from the exhaust? I exclusively purchased gas from Shell with first Porsche, because the station was 1 mile from my house and the rear bumper of that car developed a black film on it that could never really be washed off after a couple years of filling up there. I had my dealer check my exhaust system on the car, and it was functioning normally.

I wanted to know if someone knows what I'm referring to, and also if you guys typically put a particular brand (of the top 5-8 gas brands) in your GT3 and why.
(other than at the track, where obviously its nice to put in 100 octane, ethanol free gas that you can buy at the track)

I don't know what's marketing and what's real about the major gas companies and their gas, and cleaners like Techron that Chevron likes to hype, and I hope that some of my fellow GT3/RS owners do know.

OCturbo

My father was in the oil/gas business, so I know something about this subject and have replied to similar posts. It's my understanding that the major difference between gasoline at different stations is the additive package (detergents). These additive packages, like Techron, help keep your fuel injectors clean. The gas statations that I think have the best additives are shell, chevron, and texaco. That's where I take my gt3 (except there is no texaco where I live.)

997s07

The last GC-MS reports I've seen suggest all gas is functionally (no unusual concentrations of longer chain hydrocarbons) the same. Component concentrations were different depending on the season but that's for all brands.

Drifting

Thank you both for your thoughts. I'm also open to any other comments.

I wish I could remember the technical term I was told by a mechanic for why the Shell gas tended to cause more soot.

Unless I hear something else from one of you informed gentleman, I expect I'll stick with Chevron or Texaco (which is now owned by Chevron) as OCturbo sounds well informed, and I'd prefer to support an American oil company if there isn't a foreign oil company that is clearly superior.

donuts

In Canada, Shell 91 octane is the only gas that does not contain ethanol. There's lots of threads on the benefits of non-ethanol gasoline.

Drifting

I would definitely consider Shell if it was octane free, but I think all the gasoline at US gas stations has ethanol. The only exception I've every seen was at the track.

Anyone know otherwise for gasoline in America?

Mike in CA

Most car manufacturers recommend using a Top Tier gasoline which has a more comprehensive detergent package. Almost all of the major oil company brands make a Top Tier product. See the list in the link below.

It works out that a Chevron station is the most convenient for me but I also have been generally sold on their Techron additive ever since the owners manual in my '84 Carrera recommended it. If I used other fuels in that car's engine it would eventually seem to run more roughly but a tankful of Chevron would fix the problem.

I'm sure that today other modern additives are just as good. I think one of the most important factors in choosing a fuel might be to pick a station that gets a lot of business and therefore has frequent refills so that the fuel is always "refinery fresh".

http://www.toptiergas.com/retailers/

sccchiii

becoming a tougher find but you can typically hunt down a couple stations with ethanol free gas in most areas..

bronson7

I can't speak for all of us Canadians but from what I hear on this topic, most of the Pcar owners use either Petro Canada Ultra 94 (contains ethanol) or Shell 91 (no ethanol). I always use PC 94. Interesting point is when I received my car, Porsche advertises Petro Canada for their cars and give us new owners a PC discount gas card. Hopefully Ronan will chime in on this topic, being he's been around far more Pcar owners than I.

Just in time

If you look carefully you will find ethanol free gas in the US. Regretfully, at least in my market, the the octane rating is usually on the low side, like 89-90. The car will adjust to the lower octane but if pressed hard during acceleration most likely will result in reduced performance. Gasoline is gasoline and for the most part its all the same. The difference is the additives. Go with the known brands.

NateOZ

Oil Companies swap physical product all the time to ensure service reliability is maintained. Depends on the area and market if the additives are added after or before the swap occurs, but they're really very close to each other. Just pick someone that is on here as a minimum http://www.toptiergas.com/retailers/.

I normally stick to Exxon/BP/Shell just from what is available local.

gurneyeagle

Stay with the Top Tier brands mentioned above and you will be fine.

I once worked for an independent oil and gas company that owned a refinery. The gas we refined was sold to Chevron, Texaco, and Exxon. The individual companies' tanker trucks would pull up to their designated company-specific terminal where the trucks were loaded. The only difference in the product was the companies' proprietary additives which were "splash-blended" when the trucks were filled.

Keith Verges - Dallas

I go top tier unless some kind of emergency. I don't think there is a meaningful and objective way to stay current on the "best" additives. First, they are proprietary. Second, they are always subject to change, so even if some independent outfit did a test, the data will get stale quickly. I just hope for the best and do worry more with the newer DI engines that I think have much smaller injector offices and higher pressures. I think Audis early DI engines had significanct Carbon buildup problems, my old A3 spend significant shop time for it.

ipse dixit

Costco.

They have the best price.

GrantG

Here is a database of stations where you can find Ethanol-free gas (Click on abbreviation for your state or Canadian province at bottom):

http://www.pure-gas.org/