I too would like to know. I'm thinking mine are fouled up and I'm going to pull one this weekend. I went down to advance auto and they pulled up the Autolite XP Iridiums so I bought a set of those. Don't know if they are worth a crap or not though..

-X

 

i just notice autolite.... get some expensive stuff if you really want to change it like denso.

 

You guys should just stick with stock. i don't know what everyone wants to change their plugs for.

 

Spark plugs are vital part of your engine. Why spend all this money and cheap out on the Spark plugs. I would also like some feed back on what everyone has tried or is using.

 

quote=Seb@Specialty-X;131722]

You'll find that the Evo X already has a cold plug with a heat range of "8". The higher the number signifies a "colder" plug. Running the coldest possible plug is always best. You'll know if its to cold that the car won't run well under idle and cold start. The plug can misfire if its too cold of a heat range.
The colder the plug or higher the number can allow for a cooler combustion and also is good for high boost application so that the plug doesn't pre-ignite the mixture which can cause detonation or pinging. Since we already have an 8 heat range you can stick with that. 9s are pretty cold for most cars and are really mainly used for racing applications where idlinglow engine speed won't be seen very much.

Since the Evo X runs high boost from the factory, Mitsubishi already threw in a cold plug which is needed for most of us running 91 octane.

So based on that. I would actually stick with stock unless your running higher boost than the rest of us.

 

keep it stock, they are so many BS claims(adding hp etc) too with the different spark plug... don't let FLK know this thread.

take a look at this design. they say "The Worlds best Spark Plug that no one seem to want to manufacture"


http://www.angelfire.com/ak5/energy21/sparkplug.htm

 

Why spend all this money and cheap out on the Spark plugs.

The stock plugs aren't exactly the cheapest ones out there. It's very difficult to get a better spark plug than what this engine uses stock.

 

I agree but their is always room to go up to 9's.

 

Sps

When I start my car, sometimes I need to turn the key for a while until the engine starts, i'm assuming with better spark plugs, this problem can be resolved. Many times the engine did not turn on the first time and the car starts the second or third time I turn the key. So I really don't know what to do about this problem...I am looking for better spark plugs or go to the dealer for new ones.

 

I've read recently that silver plugs are the way to go. Does anybody here have a set in their X?

 

HKS Super Fire Racing Spark Plugs in 8 heat range would be ok. They are colder then stock so it would be less prone to detonation, safer for lots of boost but it may foul easy.

NGK BRP7ES is another plug its copper and Dsm'ers and Evo guys use them with great success. I used to use these in my DSM.

I wouldnt get a hotter plug

 

NGK 7s should be plenty cold for this car.

 

i think this is already iridium.... it should be enough stock wise.