I was thinking about getting the HKS spark plug for my 8...
but not sure which to get cuz theres 2 different types the s-series and the m-series...
any body know the differences between the 2? which is good for a daily driven 8?
and also what heat range would be the best?

 

Its a waste of money.

Go with Stock plugs or regular Rx7 plugs, they're the most *bang for your buck*

 

+1

 

one more thing, if you really have too much money to waste, you can try to ask the question in Rx7's forum.

Cuz the plugs that you see on the HKS site was designed for Rx7. BUT ! since Renesis can still take Rx7's plugs so they should work without any problems. You just asked a question in the wrong forum.

but again, you can get a set of OEM plugs for about 80 bux, stock plugs are pretty high quality if you ask me.