Pick the Right Plug For Power

Specialty Plugs

This is the age of designer spark plugs. SplitFire rode the first wave of specialty plugs with its V'd ground strap, and now it seems that every spark-plug manufacturer has its own version of what's hot. While the debate will continue to rage over whether diamond-shaped or split-V ground straps are worth more power/mileage/emissions, we do know that plugs using more exotic metals enhance durability. Platinum arrived a few years ago, with Bosch leading the charge with three different versions of its platinum-tipped spark plugs. Then NGK upped the ante with its Iridium IX series of plugs. The plan with virtually all these designs revolves around reducing tip or ground-strap erosion that increases the gap between the center electrode and the ground strap. Some plugs, like the Bosch Platinum +4, use four ground straps to also minimize the overall gap to ground.

The price on these plugs is also significantly higher than for normal copper-core spark plugs, and generally, the heat ranges tend to be limited. These specialty plugs are not intended as race plugs. Instead, they are aimed more at everyday drivers and may offer slight mileage or emissions improvements.