When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
my dad put some in his expedition and noticed more power but that may have been due to the fact that the old ones had a lot of mile on them and needed to be replaced
do what the factory calls for... eclectricity takes the path of least resistence so having those spark plugs with multiple littl things on it doesnt really help.