I don't have any on my Explorer, but I have run them on other vehicles. They are a good quality product and have never had any problems with them that were manufacturer related (I've seen a few burned boots due to running them to close to a set of headers, stuff like that, but no manufacturer failures). Personally I prefer MSD or Ford Motorsports (don't know if they make wires for an Explorer though), but that is my opinion (and you know what they say about opinions. They are aquality product worth the money, so don't be afraid to use them if they are what you want.