So then you would assume since they told you that the plugs are the same that all companies that manufacture products for resale by other companies are the same.......take for instance gasoline? Its all refined the same way, but shell and texaco and bp etc.....all use their own blend of additives. Pennzoil, Valvoline, rotella, mobil etc must all be the same cause the oil is all created the same and the individual companies but their logo on the bottle with their additives? How many different oil filter manufacturers do you think there are? Hint: about 3 or 4. They make them to the specifications of the retailer. The plugs are different in the quality control standards and maybe they use a slightly different composition of metal, whatever the case may be there will be some difference.

and its neighbor