For me any way, not sure if it's worth the money. Between the carbon build up and oil that invariably gets drawn in through the breather in the air box and finds it way to the left plug.....I just run what's cheap and in spec. Clean them and regap with tune up.
It's eight and a half gallons of gas; and an engine. What more do you need?-- BMW R80G/S
Save lives. Legalize lane sharing.
Cow eyes don't glow.