I recently installed 4 bosche platinum spark plugs. All i have to say is wow. They are amazing and i feel that my engine is running smother at fewer RPM's, and with a 4 cylinder and spark plugs costing $9 for 2 i have to say its a well invested 20 bucks. They are however 4 times more expensive then the cheapest variaty, but i think that they are worth it.