paranoid spark plug question.....
 

ok, my car smokes a bit......or at least, I think it does, and pulling the Bosch WR4CC plugs, there they were, some oiled up. Most of my mechanic experience is bike based, and I thought it odd the plug was so cold, a 4. I go back to a mineral 20w/50 oil, and go looking for plugs.........

So, no Bosch plugs available, I go to parts shop, and could only get Denso. The plug recommended by the Dneso book is W20EPR-U11, and if I cross reference it to a Champion, it comes out as WR7DC - both hotter than the Bosch. I fit same, car is back to full health, and I've been running it all week to quantify the oil usage.

However, got Wayne's book during the week, too, and last night I see he says WR4CC too..........mmmm, thoughts of holed pistons come to mind, and I go scrabbling for the owners handbook. It states WR7DC for with cat, and WR4CC without. Mine is without.

Question then is this: the 911 engine obviously has a tolerance for either plug, mechanically, and our climate is noticeably cooler and wetter than either Stuttgart or CA, so my car behaving as it does on the Denso, is it likely to do any long-term damage? I have detected no pinking or detonation, and until I do some more miles and a plug chop, I'm a bit unsure of it all..........

TIA from yet-another-newbie........

Welcome to the BBS. :)

In the future, please indicate your year and model when posting,

You should be fine with the WR7 plugs. The sparkplugs tell their own story. After driving it for a week or so, pull a plug and see what they look like. If you have a good burn pattern, stick with them.

AFJuvat

AFJuvat - thanks for that. Suffering from a tad too much information, I believe........