Champion RN11YCC

[Toowild78]

I can't find any information about this plug, but it's the part number out of my hand book. I can get the following 3 plugs at NAPA what is the best path to take?
RC12YC~Cooper Plus
3071~Single Platinum
RC11PYPB4~Double Platinum.

Thanks in advance.

[Disco Mike]

Either the Champion double platinum or the Bosh Platinum Plus 4, 4418.
By the way, how many miles on the engine, will you be throwing a set of 8 mm wires on?

[PTSchram]

Champion number 318, cheap, easy to find and work well in DIIs.

[Toowild78]

Originally Posted by Disco Mike

Either the Champion double platinum or the Bosh Platinum Plus 4, 4418.
By the way, how many miles on the engine, will you be throwing a set of 8 mm wires on?

Hey Mike,
106K on the clock and I have already installed a set 8mm Magnacor's about a year ago. I replaced the factory champs at 80k with a set of NGK iriduim's but have not been very pleased as the motor still had a slight mis. I went with the Champion double platinum's this morning and the motor smoothed right out. I'm a little shocked with the ngk plugs as I have used them several times in the past with good results. I even used them in my wife's merc twin spark. thanks for the replies, the plugs were $5.39each at NAPA.

[Disco Mike]

After nearly 70,000 miles on my Plus 4's, I switched to Bosh Fushions while doing the head gaskets and I was not as pleased with them either, lost some low end puch that I had grown used to with the PLus 4's.

[ArmyRover]

Originally Posted by PTSchram

Champion number 318, cheap, easy to find and work well in DIIs.

What he said.

[Toowild78]

Originally Posted by Disco Mike

After nearly 70,000 miles on my Plus 4's, I switched to Bosh Fushions while doing the head gaskets and I was not as pleased with them either, lost some low end puch that I had grown used to with the PLus 4's.

Well at at fisrt listen the mis was gone but after driving for a bit it's back only at idle. The new plugs perform better but still a mis at idle... Not sure what to do now. I can appreciate everyones opinon on the standard plugs but what I was looking for was long life. I have worked for NGK Spark Plugs USA for 14 years and the platinum and iridum plugs are a better option for 80~100k miles of service. The standard copper core start to fail during testing at 30k. Anyway no codes and going on vac. in a month any advice on where to check next? Also I use seafoam twice a year and the LR fuel treatment at every oil change 3k 15-40 Rotella K&N 3001hp. Thanks guys!!!