I would be surprised if there were 4 sparks on a +4 plug. I would think it would (as others have said) take the path of least resistance; ie: one of the gaps will be the smallest, even if only by a minute amount. As that gap wears/increases, the next smallest gap will be used. This is how I picture it, anyway.
I can't imagine much of a power increase due to different types of plugs. It can't do any more than "light the fire". Plus, I've heard of cases (have not seen it first hand) where the Bosch 2/4 plugs have "shed" electrodes in the combustion chamber. Scary...
I can't imagine much of a power increase due to different types of plugs. It can't do any more than "light the fire". Plus, I've heard of cases (have not seen it first hand) where the Bosch 2/4 plugs have "shed" electrodes in the combustion chamber. Scary...