Well,i changed the plugs and wires on my 97 F150 with 77,000 miles.Wow,what a pain in the *** the passenger side was.:-X23 Everything was going ok until i had to remove the last plug boot on #3;it broke!Man,was i mad Then i noticed i could get at the plugs better on that side going thru the wheel well;that was easy.Boy,those plugs were shot.I bet i get another 2-3 mpg with the new plugs.Whoever had the truck before me put reg. platinums in the drivers side (42E) and double platinum on the passenger side(42EG).Anyone ever heard of 42EG? Probably a different heat range.I went back with Autolite double platnium 42EE plugs and Autolite wires;now she purrs like a kitten!!!!!