Toyota denso iridium spark plugs for 4 cylinder

Toyota Spark Plugs are all resistor plugs with single ground electrodes feature patented U-goove design, resulting in a hotter spark. The Copper-tipped plugs are designed to last up to 150,000 miles before replacement. Toyota adds nickel and iridium to the platinum; this alloy helps make the spark plug strong and durable, while helping to prevent cracking. Toyota iridium spark plugs: The long-life, high-performance spark plugs,