This came out of an indy cylinder head engine and they recommended 93 octane. Problem is in my neck of the woods we only sell 91 octane. It'll spark knock with out it.
Ok, I doubt that Lucas is actually raising the octane two FULL POINTS. It may raise it .2 points but not 2 points. Very few octane boosters will raise octane 2 points.
There is far more to fuel than octane rating. I think you should reduce the Lucas octane booster by half (half of how many ounces per gallon you are now using) and work on your tune up.
Adding all that booster is IMO a waste of money. I’d have to see the rest of what your build is, but I think you’d be better off spending time on your tune up and using less booster. Or none at all unless it’s a fuel conditioner.
