Why do you guys use iridium plugs? I've always used regular, and never had a problem. Even on my turbo bike, still regular CR9E.
I run the iridiums, but change them every 20K miles. I'm paying $40 a set.
I just bought a set of NGK CR9E from ebay for 17.99 shipped for 4. Best price around. this is the link o the vendor I purchased from "NGK Qty 4 CR9E 6263 Spark Plug | eBay"
Now, that makes sense. Not that it is difficult to change plugs, but I would gladly do it less often.
Extended mileage until service is needed... is it something that the manufacturer clearly claims, or your personal decision?