Rmas99

woww. So afraid what is 95 in europe that most people use

subshooter

91 US Octane. It's fine. It's basically what most people in CA put in their GT3s.

88.5 AKI = 92 RON
91 AKI = 95 RON
92 AKI = 96 RON.
94 AKI = 98 RON.
95.75 AKI = 100 RON.

http://www.pencilgeek.org/2009/05/oc...nversions.html

Rmas99

so basically pointless to pay extra 10% for the 100 Ron? Once I had power box from techart and they strictly recommended 100 Oct only

Rxpert

I went down the fuel rabbit hole hard yesterday lol. 91 octane fuel in North America is totally fine because it’s measured using the AKI method. 91 is not okay for full throttle in the rest of the world because it’s measured using RON only.

This Wikipedia article finally clarified it for me. In particular look at the chart.

91 AKI USA = 96 RON
91 RON Rest of World = 85 AKI

https://en.m.wikipedia.org/wiki/Octane_rating

Rxpert

This is still correct from my recent research.

GrantG

98 RON is fine for GT3 (less Ethanol is better - I remember this varies quite a bit there. E0 or E5 is best)

Bxstr

I fill up with Shell VPower 93. If there was Ethanol free I'd use that, but there aren't any stations I've found within reasonable driving distance (based on the Puregas website) that carry it. This is one area I try not to overthink. I'm guessing my car will still last a very long time running the gas I'm running.

GrantG

I agree. If I didn’t have easy access to E0, I wouldn’t sweat it either.

subshooter

I use this to select my gas: https://www.upside.com/for-people/gas Of course I always use 93 octane and you can set up your screening in the app for the type of gas.

It's a great app. Saves me at least 25 cents a gallon. Not only does it find the cheapest gas in your area, but then it gives you cash back on top of that at up to 20 cents/gal.....plus the cash back rewards that we get on our credit cards. These gas stations connect with this app to bring people to their stations to spend at their store. They make almost nothing on gas. (Very low margins)

Spyerx

In SoCal….

Only a few options that website is bs:
By the pail from someone like vp. Betim can get it…
At the track
There are a couple of stations that sell 100 oct (there is a car wash in hb that does)

It’s not common and frankly not worth it. Better off getting an e85 tune and running that. Corn oil is a lot easier to find.

My 997 rs made about 12 more HP at the wheels on 100 vs 91 (with a tune for it). On track that was good for a few mph on a straight and a few 10ths

Have the graphs somewhere….

MBLocal

What are folks thoughts on Shell Vpower 93 with sub-10% ethanol vs. Exxon ethanol free?

shrimp money

This contradicts what M Engineering said in a really long thread in the 992 section. He said the higher ethanol content (up to 10%) like from Kirkland fuel is good.

GrantG

I read a little about his specialized maps for running E85 in the turbocharged cars. I’ve done that for a decade in my Evo 9 (switchable fuel maps), but have no interest in having any Ethanol in my GT3 (since I can easily avoid it where I live).

Does his rationale apply to the NA motor in the GT3 or just the turbocharged cars?

Marv

Is this splitting hairs? Unless you are really tracking the car (and lap times really matter), there’s no advantage on the street arriving at the next stoplight .02 seconds early.

Porsche seems happy to warranty their engines with the recommended fuels. So, no worries abut the engine. Nevertheless, I would rather not have ethanol in my tank if I could avoid it, however, my car is still running strong with the ‘stuff’ after 148K miles. Probably doesn’t matter.