Champion RC12MC4 plugs OK?

[dragnet]

Tired to find the RN11YCC plugs the RAVE calls for in my 03 4.6. No luck anywhere. Closest I could find was the RN11YC4 plugs. Looked in the Champion book and they recommend the RC12MC4 plug for the 4.6 motors. Isn't this a colder plug then the RN11YCC?

Would normally go to a NGK but there is not much to be found on NGK success rates using the search function. Bosch is definitely out of the question. Dealer wants to sell me the Champion RN11PBPY plug, at least I think that is the number they gave me. RAVE lists that plug for the 4.0 motor not the 4.6.

Does anyone have anything good to say about the RC12MC4 plug?

Thanks.

 

[KyleT]

NGK works great for me... run them in everything.

 

[rmuller]

I just use the Champion 7318 ...

 

[tex599]

I just bought Champion RC11 from Napa the other day, $4 each.. They had to order them, but had them the next day. Not sure of the heat range on the RC12.

 

[ptschram]

I use the Champion number 322 in the Bosch engines.

 

[wazazzle]

Tried autolite plats but switched back to coppers. Seems to run smoother now

 

[gmookher]

how can there be so many right plugs?

 

[rover4x4]

because this is the discoweb.

 

[ptschram]

how can there be so many right plugs?

Plug selection includes electrode profile, material of construction,heat range, thread size/pitch, heat range, etc. There are minute variations from one rating to the next that only Chris Shaffer would care about :victory:

I prefer the Champion 322 as the electrode is much larger than the stock and electrode deterioration is much slower. I have removed plugs from DIIs with plug gaps as large as 0.090". I believe this is due to the incredibly high current density on that tiny little electrode. I have yet to need to replace a 322 plug as they last as log as the 318s do in the DI.

YMMV, FWIW, use adult supervision, it's worth what it cost you.

PT

 

[adriatic04]

I went to the champion copper and have noticed a smoother idle. Its not just my head, others who have gotten in even notice. They may not last as long but aren't too terribly expensive or difficult to swap.

 

[SGaynor]

To answer/clarify the OPs question: The RC12MC4 plug is the Champion 322; the RN11YC is the Champion 318. Both will work, but see PT's post above - it's good info.

That said, I've used the 318s without issue, although I change my plugs yearly since they are cheap. I'm currently running the 322s - no issues.

 

[DISCODOWN]

Theres a lot of info here about plugs if you do a search. I cant speak for the Bosch engines but plain old champion copper cored plugs no doubt have worked best for me in my 96 4.0 GEMS auto d1"s...
Here is the one place where i've found cheapest is surely best.

Another high consideration to keep in mind is having good plug wires...
Cheapest not best here though i found most expensive was not always either.


There is as many suggestions here on that too if you search as there is about oil and filters and many different combo's work best for many different people. One thing is for certain is that none work well if past their service life and that seems dependent on your use and driving style factors and your vehicles condition and only you best know and should consider that.

 

[dragnet]

Thanks everyone. I'll try the 322 plugs. It's what Champion recommends for all the 4.6 Gems and Bosch motors in their application book. Since they are the OEM manufacturer of the original plugs, hopefully they know what they are doing. We'll see!