My theory was some colder plugs would help with allowing more timing and in turn better mpg.
My supercharged tacoma required 3 prong copper plugs where as the oem were 2 prong denso ones. I had to order these online by some off road company.
In my past its my experience japanese made engines work best with ngk plugs. My sidekick for example required a v grove ngk plug stock and ngk makes it.
The gen 1 guys talk about theirs needing indexed plugs and some go as far as to mark the plug and use washers to make sure its oriented correctly.