These plugs bring some of the advantages of a twin plug engine into a single plug design. Installed them in a 2005 Suzuki DL650 and the difference was remarkable - MUCH smoother response to the engine, and a much more stable idle - plus they last well. I've gotten 50,000km out of the first set and just bought replacements on spec as I'm doing some maintenance anyway - not because they feel like they need to be replaced yet. Don't go Iridium, go dual spark!