Okay. I think I've found something. I found this nifty cross-reference tool on the Denso website.

http://www.denso.com.au/sparkplug/xref

They list Bosch as an option. Selecting W9DCO, you get the DENSO W14EP-U plug as a possible replacement according to DENSO.

Go to the Champion website (not like I'd actually use these in my car). Search their site and you get their N11YC plug as a replacement.

Go back to the Denso website cross reference page and look for the Champion N11YC plug. It doesn't give you the Denso W14EP-U plug. I think it gives the W16EP-U. Does anyone know the difference between the denso w14 and w16 plugs?

At any rate, go to NGK website. Look it up by car, and I find that the m116/m117 recommendation is the NGK BPR5ES (listing number 7734). This plug has a resistor. They make a nonresistor equivalent which goes by BP5ES. Its not the BP6ES or BP7ES as some of the posts suggest on this site. Is their recommendation wrong? is the 6 or 7 series plugs better for some reason that the manufacturer's not aware of?

Again, go back to the Denso cross reference and the NGK 5 series plug matches to a W16EP-U Denso plug. Is this definitely the non-resistor plug to get?

I also searched Autolite and I found that their website recommends their number 64 plug which is definitely a resistor plug. However, if you go to the cross-reference Denso page, you'll find that the Autolite 54 is the Denso W20 equivalent and the Autolite 55 is the W16 equivalent.


Pheeew! Now that that's been said, I haven't gone to the store to see what's available and I have no experience with the general qualities of all these brands. Can someone put their $0.02 so as to what's the best bang for the buck with regard to brands?