110 Octane

[d1sc46]

Hey guy's just wondering if I can get some experienced input on 110. I have a 03 Cobra full exhaust 2.3 TVS and tuned on 93. Sounds like a dumb question I'm sure but what would happen if a ran some (few gallons)110 octane. I understand if it's tuned on 93 it's safest to not use anything else. Thanks for info

 

[stkjock]

• The Distillery

Discussion of specialized fuels, specifically E85.

so are you asking about race gasoline?


as a general comment - one should never run a fuel the car is not tuned for.

your guess.... is not correct, the higher the octane the more resistant to detonation it is

 

[railroad]

I ask a similar question on adding C96 to my 93 octane pump gas for my 13 Shelby with a tune, throttle body and smaller pulley.
I was advised not too. My thoughts were, even with the computer being adaptive, I could make a run and the engine pulling the higher octane fuel and then under load ingest a stream of 93, the timing might not be able to back down fast enough to prevent some damage. Even with the possibility of the damage being marginal, it was not worth the risk, for me. I do not know for certain this was the logic used in the advise I got, but I deferred to the experience of person I ask. My intent was to just ensure I had an octane cushion, since I have little faith in the pump numbers. I feel if you are able to confirm a consistent blend, it might be OK.

 

[fbody83]

Correct, different brands of race fuel have different stoich points. Mixing or running race gas will change the stoich which means your tune will now be incorrect. While cruising your ECU can adjust for that but during WOT it will not and that's when you can really do some damage.

 

[03Steve]

Depends on the 110.

There are typically two things at play when mixing fuel. Specific gravity and stoich point. Shell 110 leaded race fuel is close enough on both items that it mixes well (specific gravity) and has a similar stoich point (air fuel ratio won't change). When mixing fuel keep those two things in mind and you'll get a little more headroom for timing/power.

 

[d1sc46]

It would be shell 110. I was just curious if it would harm (timing) anything. Wouldn't be running it all the time. Just wanted to try a few gallons lol. Thanks for all the info