Review on Autolite XP5364 Iridium Spark Plug by Josue Zepeda

I bought these to replace the stock plugs on my Mazda 3 2009 2.3L. They looked the same size as stock ones and although I didn't have CELs the engine seemed to stall at times, throttle response was worse and fuel economy was worse than worn out stock spark plugs. I bought some Denso spark plugs instead and now the engine runs very smoothly and the difference in performance is very noticeable. Gasoline consumption has also increased. I have used Autolite spark plugs on many cars in the past with no problems so I bought them at first but my Mazda just didn't like them.