+1. However, like IRRBrogue, I too formulated motor and racing fuels in a previous life. The majority of non-authoritative info on the internet and this forum regarding motor fuels misrepresents reality. The variables affecting fuel performance are so great and the relationships so complex, that simple declarations cannot do the subject matter justice. Fuels can be formulated to maximize torque, horsepower, drivability, economy, cost, etc... Variables include heat of combustion, octane, research octane, motor octane, distillation curve, flash point, vapor pressure, etc... Discussing one variable without referring to assumptions regarding the other variables is often misleading.

 

Absolutely. It cannot be said then that high octane fuel inherently has any other characteristic that will affect performance.

 

What!? Everything on the Internet isn't true!?

 

I read an article that said everything was true. Who to believe?

 

RickyJay,
Tell them my real name.

C.O.

 

Wow, it's like I've gone back 10 years to my Subaru days with virtually identical discussions happening on the Scooby forums back then...clearly, some things never change.

Me? I just fill up and drive the thing, sorted!

 

C.O. ?

Captain Obvious from the Hotels.com commercial?

 

 

I'd like to think the quality of our bickering is better, but it probably isn't. Meanwhile, over on NASIOC, I think they're still arguing about Mobil 1. In fact, I think it's the *same* argument that was going ten years ago.

 

I see you know how to turbo encabulate.

 

This was the best explanation I’ve ever heard. Brilliant that man is.

And someone translate please. Lmao

 

Don't forget retro encabulation,

 

Why?
Does it make my car go any faster 0 - 60, or top out 200+mph?

 

Makes your wallet go from $150 to zero in .5 seconds.

 

The misunderstanding of how octane rating works is amazing... Someone pointed out that the base tune map is based on the octane that was used to develop it and that is completely correct. It sets the maximum advance, any ping detection will reduce advance. There is no such thing as continuous learning to optimize for higher octane. As unhinged pointed out, the additives play a major role and are custom picked for specific purposes. Higher octane fuel usually has higher detergent content.... because otherwise, higher octane fuels have a tendency to leave more deposits. Higher octane fuel is actually harder to ignite... The short answer to your question is... if you have a stock ECU map, in the US you need 91 octane, anything more will not help and it may actually harm your engine (exhaust valves, O2 sensors, cat converters). If you want to use race fuel, have a reputable tuning shop put YOUR car on the dyno with it and tune it for that... but then stick to it.
MORE OCTANE is NOT EQUAL to MORE POWER without ECU tuning.