".....With the Pulstar plugs, the average gas-mileage went down slightly over the course of the test. This bears out similar reports from other group tests of these spark plugs published elsewhere on the web."
you can trim the arch tip and that works great...but once you got your wing tuned up that's about all you get..unless youv'e done head, valve, exhaust and carb/inj major customizing ..!yeah right!!...why do you need more on a wing...now with the harley its a science that spits out more fire with each mod and that tickles!!