Review on NGK ZFR6FIX 11 Iridium Spark Plug by Ron Collins

I didn't really need to change the spark plugs but when I changed the timing belt I got a spark plug gasket kit and I'm glad I did. One of my seals was broken and oil got into the spark plug chamber. Cleaned, put on all new seals and exchanged all candles for these. My previous spark plugs were also NGK so I didn't notice any difference in fuel economy or performance but for the price they were worth the change. The first lasted 60,000 miles and was still good, but now I know I'll be good for another 5-6 years or so. They work, are cheap and easy to install. Just remember to check the spacing.