Why would you want to do all the work to do this every 25,000 miles? Millions of us run Irridium plugs which do cost more but have proven time and again that they are capable of good performance for 100,000 miles. I personaly am not interested in changing plugs or gapping plugs on short interval, also I find the gap growth to be unacceptable on your Champions. IMHO Champions in any variety are best left to lawn and garden enines.