[Marc S]

In Oregon which is still NOT self serve. Local Chevron whose owner is a car dude. Carries clear gas 92, 97 and 110 at pump. Is it worth running 97 for track days @ 7.99 a gallon. I realize ECU will pull timing but can it hurt running 97? They have 110 but wont dispense into car. i have to fill up 5 gal jugs

 

[baabootoo]

Why would it pull timing for higher octane fuel? Either way, it's a waste to go beyond 93. Not unless you get a custom tune.

 

[That Guy]

Why would it pull timing for higher octane fuel? Either way, it's a waste to go beyond 93. Not unless you get a custom tune.

Correcto

 

[Marc S]

Correcto

all that's available here is 92 regular(with ethanol) and 92 clear(no ethanol). Car has factory PCM and tune.

 

[VancityCat]

Why would it pull timing for higher octane fuel? Either way, it's a waste to go beyond 93. Not unless you get a custom tune.

Not quite a waste. Many of us have seen knock on 93 .

Running a few gallons of 97 mixed in with 93 would be a healthy prevention against knock and allow the computer to permit full timing advance .

 

[Marc S]

Not quite a waste. Many of us have seen knock on 93 .

Running a few gallons of 97 mixed in with 93 would be a healthy prevention against knock and allow the computer to permit full timing advance .

so if I were to say run it to 1/4 tank. fill it with 3-4 gal 97 and top off with 92 should do it.

 

[Challey Cat]

In Oregon which is still NOT self serve. Local Chevron whose owner is a car dude. Carries clear gas 92, 97 and 110 at pump. Is it worth running 97 for track days @ 7.99 a gallon. I realize ECU will pull timing but can it hurt running 97? They have 110 but wont dispense into car. i have to fill up 5 gal jugs

Be careful! If the fueling nozzle doesn't fit, the 110 octane might be leaded. You'll fry your catalytic converters running leaded if that's case.

 

[102542]

100 0ctane does wonders--just do it--good for sginificant power gains. Above 100 it will burn to lean..

 

[Xylander]

Eh, I doubt you'd get 1hp of power gain with 100 octane if you're stock or running a 93 tune. You don't lose that much advance in timing to compensate for things like power lost due to rising inlet air temps. In a clinical setting where you could blow polar cold air into the engine, sure, you could maybe get the PCM to accept 100 octane fuel for max fuel/air mix at high compression rates (cold air mass), but for every day driving out in mother nature, the heat soak is going to yank all that timing right back.

 

[JediBigBean]

In Oregon which is still NOT self serve. Local Chevron whose owner is a car dude. Carries clear gas 92, 97 and 110 at pump. Is it worth running 97 for track days @ 7.99 a gallon. I realize ECU will pull timing but can it hurt running 97? They have 110 but wont dispense into car. i have to fill up 5 gal jugs

where is this at? im in Portland thanks just curious

 

[VancityCat]

Eh, I doubt you'd get 1hp of power gain with 100 octane if you're stock or running a 93 tune. You don't lose that much advance in timing to compensate for things like power lost due to rising inlet air temps. In a clinical setting where you could blow polar cold air into the engine, sure, you could maybe get the PCM to accept 100 octane fuel for max fuel/air mix at high compression rates (cold air mass), but for every day driving out in mother nature, the heat soak is going to yank all that timing right back.

Running the interchiller on a Redeye in 60 degree temps would give you some pretty low IATs...and with the increased boost those motors see- I don’t see how it wouldn’t be a good idea to run a few gallons of high octane as good insurance .

 

[Marc S]

where is this at? im in Portland thanks just curious

Eugene

 

[Rockster]

In Oregon which is still NOT self serve. Local Chevron whose owner is a car dude. Carries clear gas 92, 97 and 110 at pump. Is it worth running 97 for track days @ 7.99 a gallon. I realize ECU will pull timing but can it hurt running 97? They have 110 but wont dispense into car. i have to fill up 5 gal jugs

On the track a bit "too much" octane is better than too little mainly to ensure the PCM need not pull timing at all. No need to run 100% 97 octane but a mix of 91/93 + some 97 to bump the octane to something over the nominal 91/93 octane is a good idea. I'd hazard a guess than something in the range of 94/95 "blend" is about right.

To contradict myself a bit in some cases race gasoline brings more with it than just an elevated octane. In some cases the engine can perform better on race gasoline used "straight" with no blending to lower the octane rating. The only way to know for sure the gasoline really offers more than just higher octane is to try it arranging to have as little lower octane gasoline in the tank as possible then put in enough 97 or whatever you want to try to ensure the engine will not be starved for fuel on the track.

Last but not least as another wise poster offered be sure the higher octane gasoline is not leaded!

 

[Xylander]

Running the interchiller on a Redeye in 60 degree temps would give you some pretty low IATs...and with the increased boost those motors see- I don’t see how it wouldn’t be a good idea to run a few gallons of high octane as good insurance .

That's a good point and a few extra points of octane in this case would keep knock out of the picture, but to go with the post I was quoting, added octane does not add any more power. More specifically, the higher the octane, the harder it is for the fuel to burn, hence why so many people run E85. Temperature management and air-fuel compression rates+optimal timing = more power. You only need the octane level to prevent pre-detonation. An engine that runs optimally on 87 octane will see not 1hp of gain with 104 octane. I can't comment on the Chiller operated Redeyes as I don't have one, but I'd need to see some data that suggests the car operates outside of its normal parameters and would require higher octane fuel to avoid PCM related power reduction due to retarded timing effects.

 

[motorheadmike]

Any Hellcat owner worth their salt up here runs a minimum of 94 at the pump (if it's accessible). Racing some guys will add an octane booster to 94. If I could get 97 I'd run it on a track day - it might be cheap insurance.

 

[Marc S]

Last but not least as another wise poster offered be sure the higher octane gasoline is not leaded!
[/QUOTE] 97 is not leaded. 110 is here locally. I just filled it with 4 gal 97 and the rest 92 clear

 

[drive_55_not]

I finally figured out my 2020 does not like pump 93 at the track. These cars have some pretty agressive factory timing , and higher octane keeps the low end timing dialed up.

I was getting a tad aggrevated seeing other stock power cars running nearly 2-10ths quicker than mine so I mixed a home brew 97 octane E17 mix like I've ran in my Mustang's and that has woke my car in good way.

It was stuck on low 7.1x @100mph with low 1.6xx 60's. Hit the 1/8th mile last night and ran my best 60', a couple low 1.54's and 7.013 @101.5mph. I cooled it down for 45min and spun a tad off the line, still ran a 7.022 with a 1.56 60'. I think that would've been a 6.99 pass if I'd stuck another 1.54 60'.

Since your starting with 92, I'd mix it 3:1 in order to bring your octane up over 95.

Mixing 4gal of 97 with 14.5g of 92 barely gets you to 93.

.