Question on Tow Setting
 

I was reading in the manual that the 87 tow setting could see some extra benefits from using 89 octane fuel. I was curious as to what those benefits might be.

I also have an 87 performance tune coming, but was wondering if it would have similar affects using the 89 like the tow. Would it be better to just get an 89 performance vs 87 at that rate?

Ok from what I understand of what Bill has told us in the past is that 87=89.
The other one is 91=93.
This how he sets his strategies when he writes custom tunes.
That's how the canned tow tune and canned performance tune are set up also.
So increasing a couple of octane points isn't going to help or hurt anything.

Correct, as Lars just said. But, you MAY be able to increase your spark timing by about 1 degree if you move 2 octane points up the scale. This SHOULD give you slightly better performance (if it doesn't induce pinging). If it DOES start to ping though, the PCM will reduce your timing even more than you advanced it, and you'll lose performance.

Ok, thats good to know. I don't really want to mess with the timing or doing my own tweaking. I'll probably end up with a piston through the block if I do. But at least I know I have the option of 87 and 89 without too much to worry about.

Thanks for the info!