Originally Posted By: friendly_jacek
I'm a big fan of denso iridium TT "super sparkplugs" (120,000 miles+, 0.4mm iridium wire and platinum tip on ground, high performance, fuel saving).
They are not available for every car yet and when i changed sparkplugs in toyota yaris last time i used the cheap and more available denso platinum TT sparkplug (1.1mm platinum wire and titanium tip on ground). I can't find anything on their expected lifespan. Should i check them at 30,000 miles? Anyone using them? Someone wrote review on AAP that the ground electrode eroded at 14,000 miles, but you can't believe what people put in those reviews.
They will last 100K min. You can check them as often as you want, but I would not bother unless you had a problem
