OldGuy

Guys a racer guy in town bought some race gas
100LL and I bought some from him to mix
with the 91 oct pump gas we have here in
Kalifonia. SHould I notice anything??
It seemed to run fine before and if
anything it seems a bit stronger now.
what should I look for??
I mixed it 3-1 pump to race.
5 gals race to 15 pump.

ca993twin

You may not notice much difference in cold weather, but in summer, it really sharpens-up the car. I usually blend about the same ratio... trying to get the 94-95 octane that the car is designed to use. Be sure the race gas you're using is unleaded!

OldGuy

Steve it is unleaded I checked that like 6 times before I bought
it from him. He is putting it in a 03 WRX subaru.

ScottMellor

It's like crack cocaine for my car.......

Steve Weiner-Rennsport Systems

Your TT will be VERY happy with that stuff,.....

OldGuy

Does the ECU sense the octane difference?
How does it sense it and what does it do
as far as performance, i.e. timing etc?

ca993twin

OG,

Steve (the other, smart one) may see this and give you the correct answer, but in the meantime, I'll just make some stuff up. Your TT is equipped with knock sensors, and when the ECU senses a knock, it'll pull timing and blow-off boost. So, basically, our cars can run on 91 octane, and not experience any real problems. However, the cars are designed to run best with 94 or 95 octane fuel, and if fed that diet, the engine won't knock, and the ECU will let that baby run to its full potential. My rough calculation says it costs about an extra $10-$12 bucks per tankful to run the blend (vs straight 91 octane). Really worth it in the summer, a little less important in the cold climates, but still a nice thing to do. I have a Unocal 76 station right around the corner from my work in Agoura where they sell the 100 octane for $4.25/gal. Come on down for a fill-up!!!!

Steve Weiner-Rennsport Systems

I couldn't have said it any better,....

viperbob

I was actually bummed recently that gas prices started to fall. We were paying $2.35 for premo, while the 100 octane was stable at $4.25. With the amount of driving I do, I fill up most times with 100... The car REALLY likes it. You have to get on it for a while for the computer to adjust to the better fuel mixture. With just the occasional blip of gas, the computer will take a while to adjust. HAMMER it for a short time and you will be very happy..

Take care. Where have you been? Driving I hope....

ZAMIRZ

technically you don't gain any power from only pumping 100 octane, you need to turn the boost up to really take advantage of the higher octane. With that said, Steve's right in that the cars are designed to run a higher octane than the 91 *** gas we have here in CA, I pump 3 gallons of trick 101 with every tankful in my 911SC and it runs great in the heat and even better in the cold. Not so much more powerful, but happier when beating on it and definately begging for more abuse

viperbob

Actually you will gain more power sooner. The knock sensors will allow more timing without the knock, which will give ou more power and boost will come on stronger.

SundayDriver

Why do you call it 100LL?
Normally that is the designation for Low Lead AvGas. BUT Low Lead in that application is very high lead vs leaded automotive fuels. I hope it really is unleaded but if you use it for a while, you will soon know for sure.

OldGuy

Mark,
I was born a poor hispanic child. I had to join the military
just to go to college. then I had to take **** poor jobs to
help me get through college to supplement the GI bill. I used
to eat top ramen when it was 5 for a buck. Speghetti was a
delicacy for me. I bought tomato paste for 8 cents a can and
speghetti sauce mix for a quarter, and would have that with
a Lucky Lager. the job I had was fueling airplanes for $3 an
hour. most airplanes I fueled took 100LL, so that has been on
my brain for all these years. So when someone says 100 octane
I just out of reflex say 100LL. Not the same stuff though.

Stummel

What tank size do you US guys have in your tts?
Do you also have the small 65 litre and the optional 92 litre tank?

I do have the small one and its barely good for 200 mls ;(

I know that you can buy the big one at carnewal but that money could be better spend...

BTW we pay like 4,15 Euro for the stuff the car is designed for and 10% more for a little bit more octanes. But you can get it at every station and dont have to mix or search for the right gas

Autobahn

Stummel,

the small one actually holds 73,5 litres and according to Viken the larger tank was not available in the U.S.