Quote:
Originally Posted by Ken911
if you still have CIS then go with the w3dpo. just feel lucky you didnt twin plug it and need 12
|
Heh. I twin-plugged and went EFI/COP - and still run Bosch OE plugs. Worked well with CIS and still do. Never had one foul, even when it was getting 6-10 mpg in-town with CIS.
Them being a heat range colder than the NGKs is supposed to be a hold-over from the factory originally thinking they were building cars for club racers to trash on the track for homologation purposes so they could go production-based racing. They made only incremental changes for emissions and never re-tested for the EPA until they went EFI with the 965 Turbo 2 (I think). And then they spec'd hotter plugs, IIRC.
Colder plugs apparently remove more heat from the combustion chamber and provide snappier throttle response - in racing, many run the coldest plug that won't foul. As spendy as they are, W3DP0's don't seem to for me in normal street usage. YMMV...