bkrantz

If you really want to get unreasonably nerdy about gasoline, you might worry about the crude feedstock going into different refineries: heavy vs light, low vs high sulfur, acid level, etc. Kinda like thinking about climate and soil for wine.

CaymanCarver

Go easy with the stuff.
Too much and you bung up the O2 sensors.

rdboxster

Top tier should suffice. Costco has top tier and generally a few cents less. Their volume is huge so will be fresh. Locally Costco is 92 octane but many areas it's 93. Locally for the BGTS it's BP as they are the only 93 octane or its Costco. When traveling we strive to use Costco as much as possible otherwise it's top brands.

sasilverbullet

If you want to read what the experts say, bobistheoilguy.com is THE forum for chemical engineers talking about oil and gas.

I've been hanging out there for over 10 years and while I'm defintely no guru, I've read what they've said and here's my one sentence summation:
All tier one gas is almost the same except for what each manufacturer puts in the fuel. Best fuel, Chevron, because it has Techron already in it.

My experience - I've owned 5 different type of Porsche's over the years. I've always tried to fill them up with Chevron, couldn't always and when I didn't I noticed a slight change in how the engine ran almost immediately. My 968 ran like crap on Texaco or Shell.

The big benefit of Techron is it ups the RON a tiny bit and keeps the fuel system, and valves much cleaner.

conceptDawg

Minor note: Chevron AND Texaco are both the same exact gasoline, including the Techron additive.
That wasn't always the case so your experience might have been before the merger.

Tom R.

Shell stations in Denver have placards talking about the new formulation and I didn't see the see top tier decals on the pump that I see on Sinclair pumps.

brur

If you were to be at the distributor supply you would see tankers drive up and load from the same tank. But you would also see the driver load a specific supplement pack matching the brand to be delivered to.
This is mostly a detergent formula. Each top tier gas supplier has its own engineered detergent. Now one detergent might be really good at cleaning some facet of the chamber, and not so good at cleaning a different aspect of the chamber. So it has been recommended to me to vary the brand from time to time to get a divergent cleaning.

TEF

If one had a choice which is better: 1) 91 Octane Ethanol-Free Gas or 2) 93 Octane Shell or Costco Premium? I have run Ethanol-Free gas for years in my 350z and the car feels more powerful and smoother than regular. However, my main rationale was the affect (or lack thereof) of ethanol-free gas when storing the car over the winter. Thus far, I have used the ethanol-free fuel in my 08 Boxster S, but have had the car for such a short time, I have no reference as to which fuel might be better.

john981

While my exhaust tips were always full of carbon build up, since I use the Arco premium fuel everything is super clean. Before that I used to put always the cheapest gas. Each time I cleaned the exhaust tips and short time later everything was dirty. Since I have changed to Arco there is hardly any carbon build ups and the engine runs much smoother in idle. I have never seen anywhere in LA the 93 octane gas, would love to use the higher octane.

conceptDawg

Between the two I'd go with the higher octane over the ethanol free unless you are storing it.

okie981

And if the tanker truck is in the parking lot filling the underground tanks or appears to have just finished filling the underground tanks, keep driving and find another station that sells a lot of gas.

When the tanker is filling the underground tanks, it stirs up water and muck that has settled to the bottom of the tank, increasing chances the contaminants will end up in your tank (mainly water as the station *should* have a good in-line filter between their tank and the pump nozzle).

NuttyProfessor

Don't get me started about cheapo gasoline. After having clogged injectors and O2 sensors causing me hell, I moved to Top Tier fuels and life is much better now. I would advise all Porsche owners to NOT burn cheapo fuel unless they were stranded and didn't have any other options.

CaymanCarver

After more research on this issue and digging deeper, discovered two things.

1. Shell V-Power - have to continuously use it in order for it to be effective. Is only advertised as being effective on "the first tank" on Port Injected engines.
2. Exxon/Mobile Synergy Supreme+ was designed to help Direct Injection engines. Seems to have more focus on cleaning injectors and adding protective coatings.. not sure what it can do for the back side of the valves.

So filled up Exxon/Mobile and seems to be a noticeable diff compared to Shell V-Power. So far so good, I plan to keep using it.

Marine Blue

I have been messing with different fuels and I’ve also found that Exxon/Mobil and Chevron seem to provide better performance in the Spyder and our supercharge Mini. I just learned that we have a local station that offers 100 octane, I’ll be using that soon!