I used the regular NGK's for $7 for 4, tell you the truth i cant tell any down grade in performance. If anything it fells better because i know the previous owners were running on the original plugs and didnt swap them out. And paying $12 a plug is crazy even though they last longer thats all the difference between the V power NGK plugs and the Platinum ones. Performance wise no difference check it out... i got this from the NGK website


Platinum

Platinum is a precious metal used by NGK in its long life and/or performance spark plugs. This is because of platinums high melting point which makes it useful in two ways. On a long life spark plugs a thin wafer of platinum is bonded at the firing point to the center electrode (and possibly ground electrode) solely so they dont wear as fast as a traditional plug. On a fine wire performance plug, the very tip of the center electrode is made of platinum so that the fine wire tip will last longer. Do not be fooled, all platinum plugs are not created equal, Platinum is a very expensive precious metal, a $2 platinum spark plug will not have much platinum in it, and therefore will not last as long as a $12 platinum spark plug. NGK platinum plugs contain the highest platinum content in the industry. Some platinum plugs have only the center electrode tipped with platinum, while others have both the center and ground electrodes platinum tipped. (By the way, it is still not suggested that platinum plugs be used on vehicles with nitrous injection. Thus far, there has been no problems reported regarding using iridium plugs with nitrous.)