My bus has NGK BP4ES plugs in it, these are long reach plugs as my heads are of the thicker type, like me These are the plugs that were in there when I bought it. Today I am getting all the bits to service my bus, I've pulled out one of the BP4ES plugs and it does look like its a little too hot. So I check the cross reference on ratwell for the equivalent bosch and find that it is equivalent to bosch W10D or W10DC, I understand the standard bosch one for my heads is W8CC, and that the equivalent NGK is B5ES, these are cooler plugs than the ones I've got now. Since I have been running fine on BP4ES apart from being slightly hot, I was planning to fit BP5ES. The "P" means that the electrode is projected. Since It has not been hitting anything and the bus has been running well I dont want to change too much. My questions, Is moving to BP5ES reasonable? What about BPR5ES with a resistor? I've always had bad radio reception and the resistor is supposed to supress interference? I have a bosch blue coil and a123 electronic disti
The end is a little on the white side rather than being tan I've only been doing short journeys lately so I'd expect them to be darker Theres nothing fancy about BPR5ES they cost £1.20 each. Well I've ordered them, I'll chuck them in and see how it goes
Funny as I won't touch NGK... I had some burn out on me after only being in an engine for 2/3 months Probably just a dodgy set, but I've never had a problem with bosch
Your plug actually looks fine to me: tan or grey-ish is nice. If it really was hot, the plug end would be really white. Having series resistors in the plugs won't really matter.
