Whats the Difference between the Standard Replacements for an AU 6 to the standard ones for An AU XR6???
Standard AU6 NGK BPR5EY-11
Standard AUXR6 NGK ZGR6B-11

and can you run the XR6 plugs in a standard 6. Any benifits

The difference is heat range, one is hotter than the other, wouldnt be any advantage at all.

kewl, thanks for the reply.
I have owned my car since 80,000km now has 126,000. Book says ford changed plugs at 50,000, but i didnt at 100,000. they had my car a couple of months ago, had problems with it, they replaced fuel pump & gave diagnostic tune, and then just cleaned and regapped the plugs, but didnt throw a new set in even though it was well overdue. Its been slower ever since, ford say its perfect but i use to pull 0-100 in the 8 seconds, now im lucky if i can get down in the 11 seconds. Its probably other stuff aswell, but it deffinately needs a new set of plugs.
Thanks again.