Review on 🔌 Denso SK16R11 Iridium Spark Plug - (3324) - Enhances Engine Performance - Pack of 1 by Fuzzhead Nelson

I recently fitted a set of four of these spark plugs to my 2005 Toyota Corolla LE and saw immediate positive results. My Corolla has been idling consistently at 750 RPM since I bought it nine years ago. The only changes made were a new set of spark plugs and a new V-ribbed belt. So I think it's reasonable to attribute the fact that the car is now idling at 950rpm (an increase of 26%) to the new spark plugs. After a year or two of sluggish starts (which I've chalked up to nine years of service), it now starts right up like a new car. It also runs quieter (it could be the new serpentine belt), runs smoother, is more responsive and I suspect it might be more economical. I have a couple of weeks to drive before I can say if the past nine years have affected the consistent 30-32mpg in one way or another. I can say that it takes less pressure on the accelerator to get the same results, so I'd be surprised if fuel consumption didn't increase at least a bit.