If high octane is this good.....
 

I blended some 100 and 91 for a 93+ octane, man car never ran better. With a proper exhaust and header with tune I can't imagine wanting way more power. Thing gets up and moves with high octane :D

its no secret this car likes 93. But much pass this its kinda a waste unless your at a track day for the added knock prevention and maintaing IAM value of 1

:thumbsup:

Unless it's tuned specifically for high octane (higher than 93) you shouldn't expect to see much, if any improvement beyond 93/94. It's not surprising (if you're at sea level) using 93+ instead of typical 91 made a noticeable improvement. Are you in California? I've only ever heard Cali 91 is about as good as pisswater...

Higher octane doesn't directly mean more power, just more thermal stability (resistance to knock). This means higher octane allows the engine to be tuned more aggressively before heat/knock become an issue again, which in turn means more power. The ECU is tuned to use pump gas, 93 being ideal because it's what is typically available. Higher octane means it's just easier for the ECU to stay in the happy range of it's knock compensation maps.

The general idea is to use the lowest octane rating that your engine is happy with. Unfortunately, our little lumps only like the expensive stuff.

We've extensively tested 100 octane and 91 octane setups on the dyno and on the track almost 2 years ago. What would you like to know? ;)

By what % is running 100 octane over 91 better? Hp/Tq etc.

The HP/TQ curve on the dyno on 100 octane is much smoother than the 91. We've seen gains between 2hp to as much as 6hp depending on conditions, cooldown, etc...too many factors. Let's just say average is about 3hp gain, but a much smoother and quieter operation. :D

We recommend people to mix a few gallons of 100 octane with 91 octane on the track. It will not, however, fix any sort of DI seal failures. That has also been proven as well. :mad0260:

I assume, this is a benefit for cars without a tune also?
There is a 103 octane pump near me... and I could fill up a 5 gallon gas tank next time I go to the track.

What about 93 octane? Of course it's better than 91, but I'm wondering how well it fares compared to 100, for instance, is it 99.9% as good as 100, or only marginally better than 91...


That's not a bad idea at all. Even if there's no additional power to be had, it's a nice safety net for a track day.

We never tuned our car. It was just a curiosity due to how "rough" the engine sounded. Based on this speculation, it's possible the engine was tuned for 93 octane from the factory but has provisions to run 91 octane on the low end.


93 octane is a good octane rating for the car. We have a 10% ethanol blend with 91 octane which is worse than straight 91 octane. The few gallons of 100 octane will also help with any sort of minor blowby that could cause a drop in octane during cornering as well. Again, it's about buffering the system. You use race tires, race brake pads, race brake fluid. Why not run a little race gas too? :)