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New to this race fuel thing so I'm looking for some insight. I have a VP fuel gas station not too far from me. They have pump gas and also jugs available. I'm not sure what octanes they have at the pumps yet because I haven't dropped by yet. I have a 2022 718 Spyder with 3500 miles and completely stock motor. What octane would be safe/good to use? I believe our 4.0 motors have a 13:1 compression ratio so what fuel would give us a slight performance boost? Thinking a 97-99 octane would be good. I'm also in South Florida at sea level. I know we want to stay away from the leaded fuels in the higher octanes. Let's hear from your experiences running these fuels in our Spyders.
You obviously want to stay away from any lead, but also avoid any Ethanol (oxygenated fuel), when possible (for fuel system longevity and ethanol has lower energy density than gasoline). Anything over 93 octane will not improve performance with factory tune. Not sure what you can find in your area from regular stations. If it's like some states, you can't easily find over 91 octane, in which case mixing in some 98 or 100 octane to that can be helpful.
You obviously want to stay away from any lead, but also avoid any Ethanol (oxygenated fuel), when possible (for fuel system longevity and ethanol has lower energy density than gasoline). Anything over 93 octane will not improve performance with factory tune. Not sure what you can find in your area from regular stations. If it's like some states, you can't easily find over 91 octane, in which case mixing in some 98 or 100 octane to that can be helpful.
Unless your car is specifically tuned for it, or you're getting detonation (spark knock) on your current fuel, you're not going to gain anything from going higher octane. In fact you'll likely lose performance.
Unless your car is specifically tuned for it, or you're getting detonation (spark knock) on your current fuel, you're not going to gain anything from going higher octane. In fact you'll likely lose performance.
Yep, best to target 93 octane as the optimum. Anything less or more is likely to be worse than 93 (this is the tuning target from the factory). If you are getting an aftermarket tune, then you can optimize different fuel.
13:1 is a decent compression ratio and I bet you can get even better results, especially on a really hot day by going a little higher than 93.
Another factor is how aggressive a MFG. is with their tuning. GM is known for being super conservative with their retard mapping and so it pulls timing if you sneeze wrong. I am not sure where Porsche lands at.
When I want to run a mixture, there are a few 100 race gas stations near me. I will start with an almost empty tank, and add 1/2 tank 100 Octane first (to make sure it triggers the sensors that you have higher octane) and then the second half with our crappy CA 91 Octane. That has worked well for me in the past. I have yet to try it on the GT4 though.
You obviously want to stay away from any lead, but also avoid any Ethanol (oxygenated fuel), when possible (for fuel system longevity and ethanol has lower energy density than gasoline). Anything over 93 octane will not improve performance with factory tune. Not sure what you can find in your area from regular stations. If it's like some states, you can't easily find over 91 octane, in which case mixing in some 98 or 100 octane to that can be helpful.
Leaded fuel is prohibited aren’t they? You can’t by anything but unleaded fuel in my market.
Shell V-Power98/99 (E0) is my default fuel for my sports cars. When in Germany Aral 102 octane gets the wheels spinning🔥
13:1 is a decent compression ratio and I bet you can get even better results, especially on a really hot day by going a little higher than 93.
Another factor is how aggressive a MFG. is with their tuning. GM is known for being super conservative with their retard mapping and so it pulls timing if you sneeze wrong. I am not sure where Porsche lands at.
When I want to run a mixture, there are a few 100 race gas stations near me. I will start with an almost empty tank, and add 1/2 tank 100 Octane first (to make sure it triggers the sensors that you have higher octane) and then the second half with our crappy CA 91 Octane. That has worked well for me in the past. I have yet to try it on the GT4 though.
Shell all the way. I have a tune and would do 1/3rd 100 octane 2/3 CA91 - pulls very nicely... Being conservative with 200cell headers and full exhaust done, tune and getting octane to about 93 or little higher - the GT4 is at about 465 to 470hp up from the 414/420hp stock number? Have not dyno'd but I think this is what everyone is saying is possible on the car without Deman 4.5. All together its very noticeable HP increase, however still leaves me wanting more...
I've never noticed any issue with 93 octane on the street. On the track, with ambient temperatures higher than approximately 80F, I notice the car will lose power towards the end of a 20-minute session on 93, and this seems mitigated by running 96 or 100. Might just be imagining that though.
I've never noticed any issue with 93 octane on the street. On the track, with ambient temperatures higher than approximately 80F, I notice the car will lose power towards the end of a 20-minute session on 93, and this seems mitigated by running 96 or 100. Might just be imagining that though.
I notice the same thing. The extra octane is not so much about gaining horsepower, but about not loosing it. Anytime at the track, no matter the ambient temperature, the AITs and engine bay temps will rise up enough to cause the engine to give up some of its timing advance. This of course leads to a slight loss of power. The addition of higher octane gas through mixing helps to mitigate this loss and keep the engine running in its highest state of tune all the rest of the time.
So don't fill up with 100 octane, but if available and you so chose, adding a few gallons here and there can be helpful. I don't do it the first session of the day, but sometimes later in the day when running for a good lap time especially when it is hot. If its is near 100 degrees, I will do it to help protect the engine.
09-29-2022, 10:47 AM
VP gas station nearby, should I fuel up?
