Never heard of anyone having a good experience with them. A couple guys I know that used them in their colorados had to replace a couple coil packs on top of the problems with the truck running. The ignition system is something that usually doesn't benefit from upgrading unless you have some serious boost or internal mods. Those sorts of claims are usually based on a vehicle that is misfiring and running like crap, something that would guarantee spark plugs to fix the problem.