I am running the quad tip Bosch plugs in my modified 2.1L engine.
The engine fires instantly.  I give the starter a quick bump and the engines starts no long cranking needed. When I had the triple plugs, it took a momment longer to fire.

When I used the triple plug in my T4 engine the head temps shot from 250 degrees to over 300+ degrees @ 65mph. I put in some quad tip plugs and the head temps dropped to between 200 and 250 degrees (less when idling).

The quad tip plugs do not run as hot as the triple plugs. This is important in the watercooled engines that are prone to overheating.

Robert

Robert