the spark plugs are Autolite XP Iridium .6mm finewire part # XP5263. ( the advance auto parts in middletown did not stock denso,or NGK.) The SRT-4 is an 05 with 6,000 miles and is bone stock. ( its my wifes car thats why there are no mods yet, but she will give in sooner or later.) The only reason I changed the plugs, is the car would skip or stumble on a cold start and if you put your foot into it at nomal speeds. It did not do this all the time . When I pulled the stock plugs they looked like new, no color on them (lean?) Thanks.
i havent heard of anyone using Autolite on their SRT. So i cant reply to how it benifits performance wise. Many pple here uses NGK, Densos, & some still have the factory still install (RR you still have yours). Their are websites, which you already may know, that you can order from. Maybe some has a set and they can better give ya some input.
My voices can beat-up your voices....
the plugs were the same thred length and over all length was the same. I have no way of cross refernceing the heat range. they are in the car now. it seems to run good. so I'll keep you posted If I run into a problem with them. The guy at advance auto said there is a 5 year warranty unlimited milage. so if there is a problem I'll return them.