By Leslie N. Bright (Leslie) on Friday, November 02, 2001 - 01:10 pm: Edit

Here's how you can tell when it's a slow day here at work....


The OEM spark-plug for Land Rovers (at least for the 4.0 Discos, I should qualify) is listed as a Champion RN11YCC. That's also what is specified in the manuals.

Everywhere you go to get spark plugs, though, list the size as being RN11YC4 (which is also referred to as a 322).

Looking at the original ones out of my Disco, which are CCs, and comparing it to the C4s, there really isn't any noticable difference...

So, with curiousity getting the best of me, I had to find out whay the difference is....


Although the original gap out of the box is different (.04 for the C4, and .032 for the CC), the big difference is in the side electrode.

The RN11YC4 is a standard Copper Plus spark plug, which has a copper core in the center electrode.

The RN11YCC is a European-only Double Copper plug. In addition to the copper core in the center electrode, the side electrode also has a copper core (the Copper Plus does not).

In the US market, Champion's Platinum Power spark plug also has the double copper cores. The Champion tech specifically warned against making the mistake of getting their Double Platinum plugs...

He said that the standard RN11YC4 should be fine, but that the RN11YCC really is a better plug, if you have a readily-available source from overseas. The Platinum Power plug would surpass the RN11YCC because of the platinum's longevity and is domestically available... but he pointed out that it is not overly merited to go longer between changing plugs, and wouldn't advise getting the Platinums over the Double Coppers if both were at hand. Although the longevity is better with the Platinums, if you change them regularly, you're wasting money on the expensive metal w/o an increase in performance.


And now we know.....




-L

By jp on Saturday, November 03, 2001 - 01:51 am: Edit

I spoke to Champ UK, and got Plats for my 3.9 97 D1 - felt better in revving, smoother. They are std spec in 4.0 and 4.6, he did not mention changing at short intervals?

By Leslie N. Bright (Leslie) on Saturday, November 03, 2001 - 06:26 pm: Edit

Platinum last a good bit longer... so, since you got Plats, you wouldn't HAVE to change them as often....


-L