After a lot of searching to no avail, I'm going to risk asking a stupid question *flame suit on*

Cliff notes: Will running 100 octane unleaded without changing anything else make a turbo Miata run cooler or improve reliability? Yes, I know it wont make more power unless I tune for it, and I'm not going to.


Long version: I have a 1.8 running 8psi w/ a gt28RS and MS that I raced in hill climbs, small circuit time trails, and autox's last year. It had some overheating issues on the small circuit time trails, which I think I've fixed with a bigger radiator and ducting.

I'm starting this year with a two day "big" circuit time trail and I'm concerned about heat and reliability. A friend recommended running race fuel because the car would run cooler. I've never heard of this before and always assumed race fuel was useless unless you tuned for it... so is he right? Are there any reliability or heat management benefits to running higher octane without tuning for it? Would it lower EGT's?

 

I've never heard of it running cooler on race fuel, but you will make more power even if you leave the tune alone. I've seen it first hand on a dyno. It will run much cooler on e85 if you're open to that.

 

It would decrease the chances of detonation, which I guess is an increase in reliability.

 

Depending on your compression to much octane can hurt your performance. Alcohol will burn much cooler than race fuel, but don't think these cars can run on alcohol.

 

Short answer is no.

 

That's what I thought. Thanks for the help.

 

Guy right below you does.

With tuning and the right parts any car can run on alcohol.

 

Coolant reroute, racer route, will help out if you havent already.