My neighbors 08 went to 60000 miles on the stockers and when he changed them during the 60000 mile service they looked like they were still good.

 

This. Replaced at 30k. Now at 53k with no issues.

 

30k on mine and still no issues.

 

2011+ got a new spark plug? Any more info on this?

 

I had failures in #4 and it did cause damage to piston and cylinder walls.

 

Anybody here have tried the denso spark plugs?

 

I tried them on my IX, but they don't make plugs for the X. Their plugs on my IX were very prone to fouling.

 

Oh ok.thnks.

 

no issues so far on the stock plugs, 31k miles. going to replace w/ mitsu branded NGk's in a day or two before tuning my EF3

 

spark fail in #1 cylinder twice both OEM Mitsubishi NGK plugs

 

Bring back dead thread.. For those who voted HKS plugs failed. Care to share what happened?

 

27k on stock plugs before i changed them, all looked great.

 

Stock plugs, 46k miles, never changed, 1 hour each way to work every day, never checked 'em, lots of mods, dyno runs and hard launch 1/4 miles. I may change them some day I guess...

 

Seems to be a common issue in the older X's....looks like I'll have to check my plugs to be sure but I haven't had any issues (yet, knock on wood). So, as it was asked before, any word on the plug change for the 2011+ and any issues with the plugs in these years?

 

We haven't had plugs fail yet, as described by these threads. Fortunately, no broken insulators etc. We have, however, had plugs seemingly begin to degrade after about 5 hours use. This is pretty consistent, meaning that the engine will begin to stumble a bit between 5-6k rpm at wot (well, really, it's almost always at wot). Replace the plugs, which tend to look ok, and the car runs fine again. Have only used the replacement NGK plugs and, use about 4 sets a season, maybe 5.

(If anybody wants a few spares, let me know, we have about 60 in the trailer.)