Good info ^^^ I believe the AL 103's are too cold for most of us. Although my AR103's were not fouled, due to having a really great wideband tune(thanks Trannyman), there is a huge difference in cold startup and excelleration between those and the TR6IX that went in oever the weekend. No more AR103's for me. I needed a couple of days on my normal route to make a final determination, but w/o a doubt my motor with my mods love the NGK.