Review on NGK LKAR6AIX 11 Spark 91187 Iridium by Frank Garahana

NGK has always made excellent, high quality and durable products. When I bought these spark plugs at a discounted price of $5-$10 (depending on where you buy them) I felt damn good. Concluded that when inspecting when applying a lubricant to the threads prior to installation, I noticed micro-cracks on the porcelain part of the connector; on opposite sides. Glad I caught it before I installed it in my girlfriend's car. I ended up having to buy ONE spark plug which cost over 1/4 the price I originally bought from Revain. Substitute.