antcee

Hello everyone. New to this board. I recently purchased a 96 993TT. Has anyone out there actually noticed a difference in running 100 vs. 91. I'm in california and there is no 93 octane here as recommend by the manufacturer. There is a 76 station that's not too far out of the way from me that sells 100. Is it worth using it? Or at least blending it to 93?
Thanks,

ca993twin

I usually blend 100 octane 1:3 with our cruddy California 91, to get about 94 octane. I figure (at $4.25/gal for the 100) that each fillup costs me an extra $10.00 or so. You will notice the difference, especially in hot weather. The TT has knock sensors which will quietly retard the timing and reduce the boost to suit whatever fuel you are using. For a long, gasoline-intensive road trip, where I'll be unlikely to be using full boost much of the time, I'd probably skip the 100, just to save the expense and aggravation of trying to find racing fuel.

Welcome to the board. First post I see. Join in.

antcee

Thanks for the info Steve. I do most of my driving on the highway. Approx. 160 miles/day , 2-3 times /week in the heat. Do you think it's better for the engine to blend?

Ruf-Racer

I don't see a need to blend 91 octane fuel for ordinary daily driving. I have run my Ruf Turbo to Las Vegas several times using 91 octane with no problems. At times blending is a major PITA! I do like Chevron because of the additives which seem to keep my fuel system clean. Happy motoring!

R

Steve Weiner-Rennsport Systems

Antcee:

You do not HAVE to blend 91 & 100 octane fuels, but your engine will make more power if you do,.... You can really watch what goes on in there with the Porsche PST-2 (factory scan tool) or a generic OBD-II scan tool with 91 octane fuel in the tank. There is quite a difference in knock sensor activity in warm to hot weather.

These engines are very adaptive and simply crank back boost and timing to accomodate the fuel thats in the tank. Whether you want maximum power all of the time is your call, of course.

ScottMellor

I run a blend at all times. I simply want to make sure I'm getting all the power that I paid for
I fill up a couple of 5 gallon cans with 100 and keep them at home so I don't get caught short.
I agree with Roland though, that for a long trip just run what you can get. Who wants to carry cans of gas around in the trunk. Why they might leak a little and strip the glue right off of the carpet in your trunk. Gee, ask me how I know that!

ggmr

I can tell a significant difference in performance if I do not mix in the higher octane gas. I buy 104 Sunoco gas from the local VP distributor in 55 gallon drums. It's cheaper and they even loan you a pump for free. With the higher octane I've found that I only have to blend in 2-3 gallons per tank to get the 94+ rating.