So I plan on upgrade my X with all bolt ons in near future. With all the power upgrade planned in mind, I met my tuner last week. I brought up the idea of E85 tune upgrade in addition to regular pump gas tune. But He told me C16 race gas is better, similar gain to E85. On the forum I have seen most of people go with E85 and was told E85 gain much more torque than race gas. Now I am confused. After reading more about the race gas, I started to wonder if C16 race gas can be mistake. From what I read, leaded race gas can cause damage to oxygen sensors and engine valves. I wonder whether C16 is leaded or not leaded, if it is a go or no go.
I am competing in autocross seriously, should I go with E85 or C16 race fuel?
Anyone has experience/knowledge with either or both, please share your experience. Thanks in advance.

 

Cons: c16 is leaded, it's expensive as hell. I ran it back then at the track when there was no e85 available. Your exhaust will have a dull grey color build up from the lead. Cops can smell you from far away. Tree huggers will hate you. You need some gas container because there's not many c16 pump available.

Pros: You don't need big injectors for c16. It could make a little more power than e85. Your full tank will last longer than e85.

Go with e85 please.

 

E85 > c16

 

race gas is always more reliable then E85, one big reason why probably the tuner recommended it for you.

if you want unleaded race fuel, i would go with VP extreme. its 110 octain, great race fuel for the Evo.

( if you go for big power, make sure you upgrade the connecting rods, that is the only weak point i find it in a 4B11T)

 

Anyone knows where to find the formula for vp extreme?

 

Race gas is predictable. Your fuel system won't hate it. No mystery goo on the injectors.
But....
It's expensive, kills O2 sensors, and even harder to fill up on than e85.