Spark Plug, Bosch - E36, E34, E39, E38, E31

• Copper tip electrode for better performance
• Hotter heat range for better fuel economy
• OEM for many models

This is a OEM Bosch spark plug used on M50, M52, and M62 engines in the E36, E34, E39, E38, and E31 models. There were two heat range plugs available and this is the hotter version (F7LDCR is the colder). A hotter plug is better for fuel efficiency. However, a colder plug is generally used on tuned engines or for track use to lower combustion chamber temps and minimize knocking. The plugs are interchangeable but the same plugs should be used on all cylinders (don't mix plug types).

Just like ignition coils, spark plugs are key to the performance and efficiency of your BMW engine. A bad plug(s) will harm performance and fuel mileage and affect drivability and engine smoothness. Unburnt fuel in the exhaust will shorten the lifespan of oxygen sensors and catalytic converters. Spark plugs wear out over a long time, making losses in performance less obvious. While BMW may recommend "lifetime" 100,000 mile replacement intervals, we generally recommend 50-60,000 mile replacements.

Bosch FLR8LDCU+ replaces F8LDCR. Both the F8LDCR and FLR8LDCU+ can be used to replace the original BMW part number 12129064617 (12-12-9-064-617). Bosch was the original supplier to BMW for this spark plug as well as most of the other ignition components and other parts and systems on your car.