alright, i was running less than a quarter tank yesturday.... so i decided to go to the nearest gas station and fill up with 94 octane..... but as the guy was filling up, i realized that the dumb **** was pumping in 89 octane!!!



so i told him to stop the pump at 5 bucks..... so my gas was about half 94 octane and half 89 octane.



well as i was driving... i realized that my car was more responsive and somewhat faster....... i dont know if that makes sense to any of you



i usually only put 94 octane in my car.....

that mix of fuel gave you about 91-92 oct.. it will still burn very fast but add just enough to not burn off too early. like the 89, or resist a fast burn like the straight 94 oct.

So Martin is better off to run on 92 octane then? How much boost?

12lbs of boost

you gotta love my vert, it runs better on 87 octane than on 94 https://www.nopistons.com/forums/pub...#>/biggrin.png

maintain 94..

additional power felt couldve been the result of other factors..

air temp.. coolant temp.. barometric pressure .. aerodynamics.. etc..

higher the octane... better your resistance to detonation..

**** it, i got some 79octane you can have.



kevin.

i was thinking things through........



im in need of a spark plug change soon, and since lower octane combust easier than high octane, i was probably burning all the fuel rather than having it combust in my exhaust.

I'm not a chemical engineer or a petroleum products expert, but I have heard that there is actually more "energy" in lower octane fuels. The higher the AKI or "anti-knock index" the lower the available power.



This seems to go against conventional wisdom, but it does not. The higher AKI lets you run the timing further advanced to produce more power.



All other things being the same, you should notice more power with lower octane fuels. But you've got to be careful!

additionally, I was told:



lower octane, higher cumbustibility (bad for high compression motors), lower flash point



higher octane, therefore, allows for higher compression with less risk of early combustion (or pre ignition, or whatever it's called)