I have Saito, OS and Supertiger engines and run OS plugs in all. Everyone of my engines runs for gallons of fuel on the same plug, seems to me $8.00 every other year is not worth worying about. If your plugs are not lasting very long I would re-evaluate my fuel mixture settings. I have tried Fox and had good luck, they seem like great plugs as well. Just be careful, don't be afraid topay fora good plug.