Mercedes® Bosch Super Plus Spark Plug, HR9DC+/7978, 1984-1993

If you're looking for the very latest in spark plug technology, look no further than Bosch Platinum IR Fusion. Fusion features a patented, fuse iridium and platinum center electrode, combined with exclusive surface air gap firing technology to produce a longer, more powerful spark. Its four yttrium-enhanced ground electrode design outperforms OE iridium plugs by significantly reducing gap wear. This means less stress on the ignition system for quicker starts, more efficient fuel combustion, and a longer performance life. In addition, Fusion's voltage requirement increases less overtime versus other iridium plugs for longer reliable performance of the vehicle's ignition system.

Yttrium enhanced copper core center electrode, making it one of the longest lasting copper core spark plugs on the market - by 50% versus even OE plugs.
Tapered V-Profile ground electrode for improved cold starts and better fuel ingnitability.