Anyone know if the stock spark plugs are platinum or iridium? Would be an easy additional HP is the stocks are platinum.
It would then still feel like 5 extra HP though. Don't get me wrong I get your point and you are 100% correct, but follow me on this. Hypothetical engine example Scenario: You have a 200hp engine, with stock plugs and 87 octane fuel you're only really getting 195hp, you move to 91 and cold plugs and now unleash the full 200hp.You're not getting "extra" horsepower. When you run 87 octane and stock plugs, the ECU will retard timing due to engine knock. This is a subtraction of power. So, when you run higher octane and colder plugs, you're getting the horsepower that the car is capable of doing with the stock "tune".
So, running lower octane/hotter plugs actually takes power away, running higher octane/colder plugs keeps it where it's supposed to be.