It seems that every car or truck has brands of spark plugs that they like and they don’t. Is there any particular brand and number plug that would work best in a 2000 4.0 Disco. I had someone tell me to only run LR plugs but of course he worked for LR what else would I expect him to say.

 

Any plug goes... Autolite, Bosch, Champion, whatever. Pick your favorite and go with it. I have the cheapest Champions I could find, they work. I don't think the most expensive Bosch +4 plats will make much difference. A spark is a spark...

 

I run NGK IR, one of the advantages of running IR plugs is they last a VERY long time

 

DIIs use what is called a wasted spark system. I found this discussion of wasted spark systems and why double platinum plugs are important on them at ChampionSparkPlugs.com stocks every spark plug made by Champion SparkPlugs!.

“… One of the two paired spark plugs is always negative polarity while the other spark plug is always positive polarity. … one plug will exhibit more wear on its ground electrode, while the other plug will experience more wear on its center electrode. If a spark plug with a precious metal on only the center electrode were to be used with this type of ignition system, there would be uneven wear on half the plugs. Although single precious metal or standard nickel plugs will still allow the engine to run, plug life will be greatly reduced.

Therefore, if a vehicle was originally equipped with dual precious metal spark plugs, replacement with a single precious metal or standard nickel plug may reduce plug life and engine performance."

The double platinum plug specified in RAVE for the ’99 DII is the Champion RC11 PYP B4, aka Champion 7070.

 

I've worked on a lot of differant brands of vehicles and I've found that Bosch plugs work best in German vehicles, NGK or ND work best in Japanese vehicles, etc. What it usually comes down to is that every manufacturer makes a plug to fit (physically) in a given engine but often the heat range of the plugs are limited. I try to use the plugs recommended by the vehicle manufacturer becuse it was designed for that application.

 

I just installed a set of E3 plugs yesterday. Now I have a "cylinder 1 missfire" code. I'm waiting for the motor to cool so I can check the plug and wire. I'm hoping it tripped because I put too much anti-sieze goop on the plug or a wire burnt; something simple like that and nothing worse.

 

i work in the commercial parts biz and i wouldnt go with autolite or champion. most people jsut use what the factory used originally, but that really doesnt matter. i used motorcraft in my ford, bosch in my bmw motorcycle, ngk in my ninja, and ngk also in my trans am (i had MUCH engine work in that beast and they were one of the few companies that made the proper plug in the correct heat range i needed).

i bought bosch +4 plats to put in my disco (that i havent gotten STILL)... mostly on seeing that thats the popular choice on the boards, and also thats what most people people ive seen here, put in euro cars. copper burns great and are cheap, but change them often. the plat and iridiums are great, but i think iridiums are overkill, you really should replace plugs often simply to make sure they dont seeze into the heads from being in there for so many years!!

the +2 or +4s should be great (especially if these engines use a waste spark, first ive heard for these motors but my motorcycle is like that) where the plugs fire on the exhuast stroke to help clean up emissions. firing twice as often as a standard ignition simple means, they will wear out twice as fast! so a longer lasting plug will hold up better obviously then a standard plug but for the same duration. having 2 or 4 posts for the spark to ground too means that when the post it most often jumps too (because of physical distance or average blow resistance of the airpattern during intake/fuel injection) wears out faster then the others, then the less used posts become the new average post, and so on! they are also good because since none of them are directly over the center leed of the plug, there is a more direct flame shock front propegation down the cylinder during combustion... in theory, resulting in a more complete and slightly faster burn... wether it is actually measurable in practice is just a bad a topic as picking the right brand of oil additive

 

Couldn't have said it better myself.
Don't pay extra for Platinum+4, there's no reason the spark will be the same