Buffalo

In California we have a minimum CLC octane rating of 87. According to the owners manual, this equals 91 RON. I have heard and think it has been posted to use premium CLC which is 91 octane.

Can these cars be run on 87 CLC or should I remain with 91 CLC. Or, just experiment with performance and detonation.

Jgordon

I believe, and hopefully someone will correct me if I'm mistaken, that our cars do not have anti-knock sensors. If you use the car for spirited driving, I'd use the higher octane (I use 93-94 Octane in an 89 Carrera) as the price of the better gas is minimal compared to the sustained damage that might occur from using a lower octane fuel. Just my thoughts.

Hope it helps.

ron mcatee

Buffalo, I agree with Gordon. On my 88 3.2 Carrera, I always use the higher octane to prevent detonation and damage. I also put in a chip and the instruxtions for using a chip explicitly say do not use Octane rating lower than 93 as it will damge components of your system. I recommend being safe and going for the higher octane. Car runs better anyway.

88 Carrera
Spider911

john#6

One other thing - don't go to a station that is in a bad neighborhood. Usually they might stock high octane, but it sits there forever waiting for guys like us to buy it and it ages out, then you've got troubles from a different direction -
Learned it the hard way when my new wife went to the wrong store -- <img src="graemlins/crying.gif" border="0" alt="[crying]" />

Jim Michaels

John: In my bad neighborhood they can't sell the low octane. We all know we need the high octane for fast get-a-ways.

Steve Weiner-Rennsport Systems

"Buffalo":

I would like to offer my observations about the numbers of 3.0, 3.2, & 3.3 litre engines that are found with broken rings at overhaul time,....

As these engines do not have knock-sensing, they are more prone to piston and rings damage from detonation. In all cases, the owners never heard a darned thing as this was going on.

I would simply offer my opinion that there is no long-term economy in using the cheapest fuel that you can find. The detonation margins in air-cooled engines are not static, these are dynamic in nature and vary with air temperature & humidity, engine temperature, load, fuel octane, and RPM.

You and your pocketbook are well served by using the best premium fuel available in your area. In some cases, even that might not be sufficient in certain conditions, DE participation for one.

Mixing unleaded race gas is recommended for 911's used in DE events in warm weather. Pump fuel is simply too inconsistent to be trusted with what is at stake here.

You may read some additional information here that might be of interest: <a href="http://www.rennsportsystems.com/~porsche.2a.html" target="_blank">Gasoline, Detonation & Twin-ignition</a>

Todd

Should premium be run in my newly aquired 73.5 CIS??