if you read on the Bosch site, here is what it says

More pure platinum with four ground electrodes and the most powerful spark.

If you require the best in performance and the longest performance life, Platinum+4 is the spark plug for you. Platinum+4's unique revolutionary firing technology combines the advantages of surface air gap technology, four ground electrodes, and a heat-fused center electrode with more pure platinum, creating the most powerful

Revolutionary surface air gap firing technology featuring multiple spark paths Delivers the longest, most powerful spark for ultimate engine performance

More pure platinum vs. Bosch Platinum For smoother acceleration, peak fuel efficiency and maximum engine power

Four ground electrodes Provides optimum access to the air/fuel mixture for the most efficient combustion…plus a longer performance life

Electrode gap is factory set Provides ease of installation - never requires adjustment

http://www.boschautoparts.com/Produc...lugs/Platinum4