Join Date: Jul 2008
Location: southwest lower Michigan
Used it for 10 years+, 11:1 406 SBC with iron heads with zero problems, and half my friends have used it too. It's not all that different than 108 octane race gas sold today. Has to be jetted a little richer and richer idle restrictions. Roughly 104 octane at the richness levels a performance automotive engine runs at. I've got a shoebox full of low 11/high 10 second 1/4 timeslips in a 3400 lb car using it. Some of those friends are spraying 250-275 Hp worth of nitrous on top of Avgas. no problems there either, it's all in the tuning.
I'm using E-85 now, in a 13.7:1compression aluminum head 406 simply because it works and is everywhere around me and easy to get, added plus it is even cheaper to purchase than pump gas and less than 1/2 the price of AvGas. If it wasn't around, I'd still be using Av
100LL is spec'd to be minimum 99.6 octane at full lean, and 130 octane at full rich for aircraft use.
If you get bad results in a car, it's your carb and timing tune-up, not the fact the fuel is "AvGas" that is the problem.
The "only works at altitude" crap was started by race fuel manufacturers, to steer guys into buying their product instead in the 1970's. Seems like this got stuck in some guy's heads, then repeated around the bench racing table, and now a ton of people believe it because it sounds plausible to believe "aircraft fly above you in the sky, therefore high altitude, therefore it don't work at ground level" because if fits with basic simple thinking.
One of the great all-time myths in the hotrod community, along with "high nickel" SBC stock blocks, "can't cruise a high stall converter on the street you'll burn up the trans", 'big cam engine don't make enough vacuum to open the secondary's on a vacuum secondary carb", Ford engines "need a little backpressure to run right", yada, yada, yada that shade tree hotrodders actually believe as gospel.