baboon

I've just got my first porsche... a 2002 996tt and love it but was wondering is someone could clear up the differences in the RON figure of gas to use.
Porsche recommends 98RON but here in the UK it's sometimes hard to find. BP does 97RON, Tesco has 99, sometimes i can only find 95. What do these numbers actually mean and what effect will they have on my car?
Thanks very much for any help

Woodster

Guys in California only run 91 octane,
Guys in Minnesota (me) run 93 octane (oxygenated) or 91 octane non-oxygenated (preferred).
some guys mix 100 octane with above but it is an awful expensive habit!!
Pour in some fuel and drive it!
MK

baboon

I've had it a week and i've hardly got out of it at all. I've found my soulmate!

Fred R. C4S

Baboon,

From your message, I see that you're in the UK. In Europe, gas is rated by RON (Research Octane Number) while in the USA we use the AKI (Anti Knock Index). AKI = (RON+MON)/2 MON is the Motor Octane Number. As if we don't have enough confusion over english and Metric units, we have to deal with the misunderstanding between areas of the world on octane ratings. Here is a link with an explanation:

Octane Explained

You can do a Google search for more information.

I would guess that your UK owner's manual will explain the recommended and lower limit RON that you can use.

Cheers,

wross996tt

OCTANE is rated in Research Octane Numbers (RON), Motor Octane Numbers (MON), and Pump Octane Numbers (R+M/2). Pump Octane numbers are what you see on the yellow decal on the pumps at the gas stations and represents an average of the two (in the US). MON test method is more relevant to racing. Most other companies advertise RON because it is higher and easier to come by. Don't by fooled by high RON numbers or an average. MON's are the most important for a racing application. However, the ability of the fuel to resist preignition is more than just a function of octane.

Stummel

95 RON is the minimum and 98 RON is recommended. On hot days and under full load you will feel a difference in acceleration. So try to get the 97 or better 99. With stock ECU a higher than 98 RON will not give you significantly more power.

bdhill

Will leaded racing fuel, like Cam 2, ruin the catalytic converters? Or, is it safe to run?

ltc

It depends on which CAM2 you refer to. 100 and 104 octane products are unleaded, 110 and above are leaded

I run 110 octaane in my son's 80cc kart....it's also dyed purple, which they do for race fuels in order to help identify them quickly (avoiding problems when filling, going thru tech inspection etc, which is a bit weird at first):
http://www.racegas.com/fuelspecs/sunocostandard.htm
it's leaded, which will cause problems for your cats

Here's a link to the Sunoco race fuels page for further details and complete specs:
http://www.racegas.com/fuelspecs/default.asp

and a link to help locate a supplier:
http://www.racegas.com/gt100locals/g...alsmainASP.asp

ltc

BTW, higher octane will not provide additional horsepower, it will help prevent pre-ignition (detonation) in high compression engines. Higher octane fuels burn slower.
A search thru rennlist will yield some good prior posts on this topic.

t urbo

Baboon, Any shell station does 98 ron and some of the tesco stores in the south do 99 ron, but bp do 97 ron which is fine. To be honest ive run my car on 95ron and 100 ron out in germany and i cant honestly say i noticed any difference.

sirees01

hey baboon congrats on the car m8.

I too am a new 996tt owner (august 05 purchase) 2003 996tt.

I came out of a CL600 for the Porsche & even though it took me a week or so to get used to it, I absolutely love it.

I have used the higher RON for my cars occasionally & it definately makes a difference.

Shell Optimax is the best IMO, the car performance is definately improved & you get more MPG's to the gallon also I can confirm the claim.

here's some info from the Shell Optimax website

Shell Optimax is a High Density High Octane unleaded fuel. The high density of Shell Optimax means that a higher mass of fuel is packed into the same volume. Because Shell Optimax is a high density fuel, in some vehicles this can lead to improved fuel economy.

wait until your tank is nearly empty before filling with Optimax