3.2L spark plug question
 

I have a twin plugged 3.2L with euro P&C's. I cannot remember why I used Bosch W4CC copper spark plugs on this engine. The factory plugs for a Carrera are WR7DC. The electrode is more recessed on the W4CC plug. Does a euro Carrera setup need the lower profile plugs?

Jon

The US plug is a WR7DC and the Euro plug (higher compression) is a WR5DC. I don't know how twin plugging effects this. I think I'm running WR5DC's in my 10.5:1 twin plug motor. I would be curious to know how the "correct" plug for an application is determined.
-Chris

My old plug is on the right.

I cannot locate any W4CC plugs in Orlando. What is the difference between the W4CC and W5CC (temp)?

Jon