Champion RN3C OE108/T10 Spark Plug Copper Plus

The Champion RN3C OE108/T10 Copper Plus is a copper-cored spark plug with a nickel-alloy centre electrode. Its copper core draws heat away from the tip, widening the range of driving conditions the plug tolerates without fouling or overheating.

Champion’s heat-range letter and number system dates back decades. Copper Plus types are natural replacements for classic cars, motorcycles, marine and garden engines originally fitted with Champion, and are standard service plugs on many later vehicles. The plug is easy to gap and inspect, with rugged construction suited to engines running rich or being started infrequently.

The heat value on the NGK scale is a conversion of the Champion heat number to help compare plugs from different makers. Cross-references can be half a heat range apart, and values may have moved up or down over time where no direct replacement exists. Treat the conversion as a guide and check the recommendation for the vehicle.