autolite app985 or xp985 plugs and an air filter.

now that there are multiple coils on a rail with no spark plug wires and distributor the parts list went way down. you may need spark plug boots but the OEM ones last a long time.

 

X2 and those are the exact spark plugs I would choose and/or recommend too. My #1 choice would be the XP-985 which is iridium-tipped and good for 200k miles.

 

@Jerry_Bransford or @Ironhead_jed how often/how many miles is recommended between plug changes? Our new LJ has 58k miles, but since they are probably the original plugs they're 14 years old - is it time to change them?

 

Yes for sure, 58k miles is at the upper limits for the OE conventional plugs. Make sure to avoid any single-tipped platinum plugs like the Champion 3034 or Autolite AP-985. The above recommended Champion 7412, Autolite APP-985 (both are double tipped platinums) or the 200k mile Autolite iridium XP-985.

 

most double platinum plugs like the app985 are good for 100k miles
most iridium tipped plugs like the xp985 are good for 200k miles

best way to tell if yours are in need of replacement is to pull them and take a look. IIRC, the OEM plug for 05 would have been a double platinum from NGK

 

Mine had 94k on the clock and they were destroyed. Should have been done at least 20K earlier...

 

I'm still a fan of OE copper plugs. Reading your plugs is a good way to gauge the condition of your engine and possibly catch an issue before it becomes catastrophic. So, I'll be looking at my plugs, checking the condition of my engine 4 or 5 times to someone running 100K mi platinums.

 

couldnt you just pull a plug or two every 20k miles and achieve the same or better results?

 

Thanks everybody for you replies

 

I don't need to look at my spark plugs to know I'm using oil, or coolant.

That said, I don't see me ever running a set of plugs 100k plus miles tho and definitely not 200k...

 

The stubbornness of some in insisting on running nothing but conventional spark plugs amazes me. It's your decision of course but that doesn't mean some like me won't laugh and shake our heads at the refusal and the reasons given.

 

No doubt the double platinum plugs are superior to OE style copper plugs.
They last longer.
They ignite the fuel mix more efficiently.
They are less likely to foul.

For me it's a cost/benefit equation. So does the superiority of the platinum plug provide a substantial benefit in a 4.0l I6 jeep to justify the cost?

They last longer--I see no benefit, plugs are easy to change.
They ignite the fuel mix more efficiently--I'd like to see a real world comparison. If I were to switch, how much better would my gas mileage be and how much additional power (dyno results) might be achieved? I suspect that the gains would be nearly imperceptible.
They are less likely to foul.--This has not been my experience with platinum plugs, it has been my experience that if you have an engine that burns a little oil or runs too rich or lean the platinum plugs don't fair well at all.

I did not make the decision to keep the copper plugs without considering all of this. Actually I like double platinum plugs, it's what I run in my SRT Charger. (plugs alone for that was nearly $250)

 

Spark plugs are one place I never deviate from OE. I don't care about what metal it is or how many tips it has, I want the actual OE part. Not that I'm recommending paying dealer prices for them, but I don't care if it's a $3 Champion or $30 NGK, I want the original spec. Not one that "fits" or is "better", I want original.

 

For me a spark plug job is so easy and inexpensive on a 4.0l Jeep I don’t personally feel the need to install a 200k mile plug. For me 200k miles would be like 2 lifetimes. On difficult access vehicles sure why not, but It gives me something to do when I’m bored vs participating in a spark plug argument.. Lol.

But to each his own.

 

Yet here you are.... participating

 

I only searched for a few seconds and this isn't a jeep ..

 

The difference is hardly worth noting . . . the fact is that neither you or I would notice that 1 ft.lb. of torque.

 

Well again that isn't a jeep and as such isn't definitive but that chart shows 4 hp and 6.5 fl/bs difference... definitely enough to notice...

 

How about a Crown OPDA... Based on the brief history I have with the 4.0, that would be on the "tune up" list.

 

Good point! that should be at least on the things to check list!!!

 

$8.32 difference over 10 years assuming 20K per year. Or $0.83 per year. Hardly equates to "greatly favors dbl plat"

And I've checked my plugs 10 times, rather than once in 10 years. I'll be able to see if I have a valve stem seal weeping oil, a fuel injector that's partally clogged, or even a small coolent leak long befor it becomes a catistophic issue.