Well if you dont need high octane theres no use in running it... Matter of fact your losing power.
I run nothing but the DIRT Cheapest 87 octane in my car. Nothing even name brand. Same thing I run at the track. Crap cheap 87 octane. Runs mid 12's and get 24mpg.
Sky
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-1989 Saleen Mustang #406- TFS Heads, E-303, edelbrock intake,70MM TB, 73mm MAF, off road H, headers and 3chamber flows.
12.55@107mph
Runs on 87 Octane and gets 24mpg!