Hello,
I'm trying to learn about the use of higher than standard octane fuels in a 335i. I have put nothing but 93 octane gas in this car since the day I got it. I have a JB4, and I have all the normal performance mods in a pile on the garage floor waiting to be bolted on (DCI, air scoops, catless DP's, FMIC, chargepipe, BOV.) When I get all of this stuff on, I was going to switch from map 1 on my JB4 to map 5. I've been reading about map 7, and was curious about the power differences between maps 5 and 7.
In my area there isn't much high octane fuel available. The airport sells avgas (100LL) which is leaded fuel. Since I will still have secondary cats and o2 sensors, I'm hesitant to run this in my car. I've looked around and there seems to be nothing but negative feedback on this.
There's a place 17 miles from me that sells "260 GTX" which, according to the Sunoco Race Fuels page, is a 98 octane unleaded fuel. Is this worth investigating further? Is 98 octane "good enough?" Do I need 100? Is the avgas as potentially damaging as I've read? These seem to be my only options after an exhaustive search of fuels in my area (zip 18447.)
Thanks in advance for any input.
