Types of auto plugs

[prkaye]

Can someone help me understand the numbering convention of auto plugs? I have a lightspeed and my engine came with Denso W24EMR-C plugs. The manual says "use only Denso plugs starting with a W or NGK plugs starting with a B in their designation." But there are many different part numbers of plugs that start with W (or B).
http://www.sparkplugs.co.uk/pages/te...-cross-ref.htm

What are the differences between these? How do I know which ones would be best for my engine?

[fl-mike]

The Denso's are hard to find, so I used some NGKs. The engine ran noticeably rougher. I ordered the Denso's from Klaus, and all was well once again.

[RV-4]

Hi Phil

Send me an e-mail and I will send you a chart that explain the number terminology of spark plugs..

It should help you.

Bruno Dionne
rv4@videotron.ca