That's hilarious. I also have a 2008, but it lists a 30k interval.

I bet they started losing sales because almost all cars go 60k+ before they need new plugs, so they've decided to stop using crappy copper plugs that were "required" before.

 

nothing crappy about copper plugs they work the best for that situation.
What u may not know is that b4 any engineer makes plans for an engine design the firing status they decide what plug to put in. The plug is the last thing to work so its the first thing to decide on because the Resistance of the plug is what will be needed to make the correct voltage and dwell time or today's cars with coils and so on.

 

So what you're saying is that the bean counters ask the engineers to save 3 cents per plug by using old technology, and then the engine is designed around that old technology? Yeah, I feel a lot better now.

Anyway, there's clearly some wiggle room to successfully use longer life plugs, because that's what Chrysler is doing with essentially the same Hemi engine, right?

 

Just a few things

Your Sig says 2008 Aspen. And since you mentioned it , I will assume its a HEMI. For 2009, the spark plug design and configuration has changed. It is a different animal, from your 08. As for Wiggle room On an 08...........The answer is no.. The uses of ANYTHING but a Copper core Plug WILL cause a Quite marked loss of performance and economy.

A premium Plug has NOTHINNG to do with life span (although they do last longer, But that is only a "Side-Effect" of their intended purpose). Platinum, Iridium and any other rare earth metal has different conductive properties from Common Copper. Therefore, the propogation of "FLAME FRONT" or "KERNEL" can be drastically altered by the use of different metals. If the engine is designed as such, it can benefit from this alteration. If it is not, It will not. Use of a premium plug in an engine that requires the use of standard plugs, can lead to misfires, damaged valves, damaged pistons, or at minimum, Loss of performance and economy....

Now , on a personal note, because it is a peeve of mine.......Your Sig says 2008 ASPEN, All Options.
So let me get this straight....You Bought Chryslers FLAGSHIP SUV, and it is equipped better than most peoples livingrooms, But You are Griping over SPARK PLUG REPLACEMENTS AND MAINTENANCE..??????? WHAT GIVES???

 

Thanks for so much great info - I appreciate the time you put into this forum!

Re: griping about maintenance:

1. I am griping about the maintenance being unclear. There are too many rulebooks, and each dealer seems to use a different one.

2. Having purchased a nearly $50k loaded SUV, yes, I am a little annoyed that Chrysler didn't follow the lead of nearly ever other manufacturer out there and use an extended life plug. 30k for plugs is almost unheard of these days outside of exotic car circles.

I maintain my Aspen religiously, and it gets upgrades. The stock shocks suck, so it has Bilsteins. The stock brake pads and rotors also suck, so it has EBC's. It runs full synthetic oil which gets changed every 6k per the manual, it gets all of the short-interval spark plug and axle fluid changes, etc. I don't mind spending money on necessary items, but it's not unreasonable to expect Chrysler to use plugs that last longer than 30k miles.

 

Ok, ..I think You missed the point......They ARENT EXTENDED LIFE PLUGS. Lifespan has NOTHING to to with it.

PLATINUM, Iridium, YTTRIUM are all Designed to perform differently under certain conditions. Things like Heat dispersement , Quench Area,and all the other technical MUMBO that only an astro-physicist would understand, are taken into account based on proposed cylinder dimensions , valve placement, Camshaft profile, and emissions standards.

The fact That they do last longer than copper plugs, was not Intentional, but rather a By-Product of what the engineers set out to design. The truth is, the longer lifespan of these plugs was an ACCIDENT.

The 09 and newer vehicles have had extensive redesign to their cylinder heads, which will now reap a benefit from the function of a premium plug, where as the previous design, would not benefit, and in most cases would react quite negatively to these differences in function.

I will give you a point though....The engineers didnt consider the consumers During design. But that is the same with any MFR.

I can PROMISE you that you will be severely unhappy with anything but standard copper plugs in your 08 HEMI...

 

^ So in my 09 vvt Hemi, I can use a premium plug, but still have to change at 30k? What plugs work best in the 09s? I'm not near there yet -- only at 12k, but it doesn't hurt to plan ahead (in order to watch rebates/sales).

 

under the hood is a white sticker on there will be the part number for the plug to use and the gap as well.

 

^ Thanks. (duh to me). I knew the gap was always listed under there, but didn't realize the plug was as well.

 

I know it goes off topic a bit, but since I see how this thread is going, I thought I should mention it....

I am NOT going to get into the debate over "Conventional" or "Synthetic" oils, because everytime I do it turns Ugly.....Unless the vehicle SPECIFICALLY REQUIRES it...Its your choice.

BUT...ANYTHING EQUIPPED WITH A HEMI, or anything equipped with Either MDS or VVT...REQUIRES THE USE OF 5w/20 Motor oil EXCLUSIVELY....

And in case you make a mistake, and use the wrong oil......He will be glad to tell you..

The oil control solenoids, and MDS solenoids are monitored by PCM for the amount of "BLEED DOWN TIME" in the respective system. Changing Viscosity, changes the bleed time, and PCM defaults the VVT and MDS systems, and sets a Check engine lamp. The DTC will read Improper viscosity lubricant.....