Plugs have 130K and mpg same as when new,Why?

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I bought my 01 mitsubiti Montero Sport with a 3.0 new in 01 . I havent had to replace my plugs or wires in 130K. It performs & mpg no different since new. Average trips Hwy/road ,or fwy typical hwy mpg since 2001 has been 19 to 22 mpg.
Anyone got any ideas how why so long? I may never be able to get them out when that time comes though.
 
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Those iridium plugs last a good long time. I've run a couple of sets beyond 100k. When they got changed I looked at the old ines and they still looked and worked just fine.

Btw; I had a 2000 Montero Sport, same engine. Great vehicle.
 
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I was shopping for some NGK or Denso plugs recently and noticed three different types of Iridium plugs all prices within a few nickels of each other. So I emailed one of the guys on here about it and learned this:

Originally Posted By: namegoeshere
The laser is the best plug the ix the worst, the IX has a single precious metal electrode, the long like a thicker core and the laser has precious metal on both electrodes.
 
They just haven't yet reached the point that spark strength is affected. I, personally, would rather replace them early than push them until I find that point - such experiments can be hard on other ignition components. But I, too, have seen plugs with plenty of visual wear on them that hadn't yet started to affect how the engine performed.
 
California weather makes the plugs happy
smile.gif
 
Any vehicle with engine management computers and fuel injection can have uniform
MPG performance over several years and 130K - that's the new normal.

However, if you ever get an engine misfire, get to it right away, most cars have
at least 2 cat converters that will get burned up by raw gas from a misfire, then you're
looking at $$ to replace the cats.
 
Yep! I never had a part fail. I did replace timing belts at 80 to 100K and had them replace the water pump,hoses belts,thermostat,but thats all. I am amazed too,so last year I bought another one. Same model etc Has 140K
Im neglectful on maintenance too,
 
Yes,as I recall chevys and fords recommended 6000 mi plug changes and I think points were the same. I followed their recommendations until I was 19 or so and found 20K was fine. Oh sure,if I romped the engine it might miss at the points or plugs,but i still got 15-20 hwy with 283,289 and 351 engines....as I recall. By 72 or sos I put in a mallory light distributor insert and never had to screw with points again. Best 20 or 40 dollars(I think) I ever spent
 
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the mpg might be the same but you may have lost a little performance and not noticed.

your decision now depends on if you ever want to do it or not.
if you see yourself doing it eventually, might as well do it now so you get use out of the new plugs.
 
Originally Posted By: PalmSpringsSCal
Woops I had a brain [censored].It has 230K mi not 130K


So... 230k miles on the original plugs? Niiiice.

I suppose you could go by the good ol' "if it ain't broke don't fix it" motto and just leave them alone. How much longer do you plan on keeping the vehicle?
 
A lot of the aftermarket iridiums with the single tiny iridium tip are really best for modified engines. They're supposed to provide features that might survive a mod better or work better given the modification.

The NGK Laser Iridium (and Denso Long Life Iridium) is an iridium center electrode with a platinum puck on the ground electrode. That's really meant for longevity. I don't believe the precious metal tips are quite as small as the aftermarket versions.
 
For what it's worth: I recently replaced the original spark plugs on my brother's 2008 Camry 4 cylinder at 165,000 miles and they looked surprisingly good. They were the original Denso iridium plugs. The owner's manual states they should be changed at 120,000. The car was running fine before we changed, and the new ones had no effect whatsoever on how the car runs now. The electrodes were a bit eroded, but nowhere near worn out completely. I'm quite confident the original plugs could have kept going for a while longer before causing a misfire - but who knows for sure?

If the plugs in your v6 are really hard to get to, just wait until (if) you notice misfire and then deal with them.
 
Originally Posted By: Ammofirst
Go for the record


He'd have another 50,000 miles to go on those, since I pulled the original factory iridium plugs out of my Fusion with 215,000 miles on them.

The crazy thing is, based on the overall condition of the plugs when I pulled them, they probably could have gone another 50,000.. maybe 100,000 miles more.
 
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