Platinum plugs or not?

My 99 JGC hit 100K miles so decided to change spark plugs, thinking they were platinum. Was amazed that they were copper core and lasted that long. Two dealers said to go with platinum, my dealer said Jeep does not recommend them. Found an article that said the platinums are incompatible with the setup with a coil per plug and can confuse the computer due to potential reverse polarity. I want long life but don't want to screw up the vehicle! What's the real skinny?

My 99 JGC hit 100K miles so decided to change spark plugs, thinking they were platinum. Was amazed that they were copper core and lasted that long. Two dealers said to go with platinum, my dealer said Jeep does not recommend them. Found an article that said the platinums are incompatible with the setup with a coil per plug and can confuse the computer due to potential reverse polarity. I want long life but don't want to screw up the vehicle! What's the real skinny?

In the same boat as I am curently doing a tune up and looking for spark plug recomendations myself. I am a GM mastertech so this is nothing new only problem is I am not up to date on DODGE and the old school rule of thumb was always to put Champion plugs in Dodge vehicles only as they will foul out in EVERYTHING else. I have learned to hate champion plugs over the last 25 years and am not looking forward to putting the god awfull junk plugs in my 98 Grand cherokee. which is why I'm researching my options. Generally platinum plugs are for long life and high mileage applications the coppers work perfectly well but unlike the platinums they wear out more quckly. the upside is you can tell when they are worn simply by looking at them. platinum plugs can look brand new at the tips when pulled out of vehicles with 120,000 miles on them. I haven't pulled the original plugs out of mine yet but if they are not platinum then I will most likely replace them with a NGK spark plug as I have never had a problem with those plugs in over 30 years and they are superior to most performance plugs as well as dirt cheap. Best of Luck

My 99 JGC hit 100K miles so decided to change spark plugs, thinking they were platinum. Was amazed that they were copper core and lasted that long. Two dealers said to go with platinum, my dealer said Jeep does not recommend them. Found an article that said the platinums are incompatible with the setup with a coil per plug and can confuse the computer due to potential reverse polarity. I want long life but don't want to screw up the vehicle! What's the real skinny?
In the same boat as I am curently doing a tune up and looking for spark plug recomendations myself. I am a GM mastertech so this is nothing new only problem is I am not up to date on DODGE and the old school rule of thumb was always to put Champion plugs in Dodge vehicles only as they will foul out in EVERYTHING else. I have learned to hate champion plugs over the last 25 years and am not looking forward to putting the god awfull junk plugs in my 98 Grand cherokee. which is why I'm researching my options. Generally platinum plugs are for long life and high mileage applications the coppers work perfectly well but unlike the platinums they wear out more quckly. the upside is you can tell when they are worn simply by looking at them. platinum plugs can look brand new at the tips when pulled out of vehicles with 120,000 miles on them. I haven't pulled the original plugs out of mine yet but if they are not platinum then I will most likely replace them with a NGK spark plug as I have never had a problem with those plugs in over 30 years and they are superior to most performance plugs as well as dirt cheap. Best of Luck

I use copper in my '96, but im sure the dealer told you to use platinum plugs because they just wanted to make more money. I changed my plugs and wires at 140k last year and i can tell that it improved the gas milege slightly. I aslo used NGK plugs, not champion.

It depends on what year Jeep and what motor you have.
If you have a 4.7L V8 HO (high output) motor, here is what Chrysler says-
Type: RC7PYCB4 (Featuring a platinum rivet located on the tip of the center electrode)
HO ENGINE CAUTIONS:

"Do not substitute any other spark plug on the 4.7L H.O. engine. Serious engine damage may occur."

If you have a standard V8 or 4.0 liter, platinum plugs are a waste of money and may not work as well as copper plugs.
Champion copper plugs are recommended by Chrysler.
Your owners manual states which Champion plug number is correct.

Stick With What Chrysler Says

I don't know why everybody won't change to better plugs. I have a 1997 Jeep GCL with 5.2L engine fully loaded, with 325000km. I've replaced my plugs with "Bosch Platinum +4" replaced wires with high performance wires, put in a K&N high flow air filter. The jeep runs so much smoother, quick starts, and the mileage is ranged from 25 to 30 mpg depending on speed. If I drive around 60mph I get about 28 - 30 mpg hwwy. I love my jeep I bought it when it had 270000 kliks on it. I've even replaced the speakers cause they did'nt work, with Sony Xplodes 220watts in fronts, with Sony Xplodes 260watts in rears, in the inifinity Gold system. Kept the same amp and stereo. Very beautiful sound system now. I can crank it up and not blow anything. Horsepower has increased at least 28%. Very reliable for me and my wife even when 4 wheeling. I am the 2nd owner of this Jeep and its my first due to the consumer guide ratings. I hope more people out there are enthused about their jeep as I am. I had one major/minor problem the rear end whined but for $400. I got it fixed at my local garage, this included new e brakes, 2 - lm603012 Bearings, 2 - lm603049 Bearings, Lucus gear oil and labor of $180. I have some other locals that own jeeps, 1. with 1995 Jeep sport has over 900000 kliks and her only problem she had to replace the tranny about 6 months ago other than that regular maint. sched and thats it. the other has over 700000 kliks and no problems. So why the longs faces about Jeeps

mileage 25 - 30? u sure?

Champions works for me

You bet I thought there must something wrong so I checked it again last night when I went to the city which is an hour away from where I live. It registered @ 25 mpg doing 75mph on hwy. I also put Lucas upper cylinder Lubricant every oil change.

natusii, tell me more about your jeep. Not to turn this into a milage thread, but tell me man; What size tires you rollin on; what maintenace procedures do you take to get them figures

If you checked my posting earlier, I explained the things I replaced. My scheduled maintenance are as follows:
Change oil and filter every 10000km using 1 bottle of Lucas Oil stabilizer and four bottle of 10/30 oil. Check K&N filter clean if necesary. Check plugs. etc. My tires are Michelin 235 70R/16. What more do you want I thought everybody does this and gets good mileage. Check my message for 7/06/2006. I baby this thing cause it's one of the best vehicles I've ever owned. I even tow a 12' trailer I may lose few kliks per gallon but still it is worth my investment. When I run my air conditioner I get about 22 mpg or so.

325,000 Km = 200,000 miles ( X .621371)

I think the way you switch from Km to Miles in your posts might be throwing everyone. 30 Km per gal would be 18 Mpg highway and no real biggie.

Me = Autolite 985 At $1.50 ea who cares if they go 20K?

Sorry buddy but I switch the over head read out to mpg. It reads 11 kpl which is 22mpg @ 75 mph. or as I said before 25 mpg which is between 9 - 10 kpl. I'm not that stupid...
Also use the proper conversions 1 mile = 1.609 km. to covert to miles you divide 325000 km by 1.609 = 201989 miles.

Where in my post does it say 30km???
We're Canadians not idiots. eh

i run platnum 4's in my jeep and i like them i also refuse to use champion plugs in anything just like the gm tech. the 4's did increase mileage a bit and did improve economey but they also wore out at about 15k. i myself really like ngk plugs for just about everything but have not tried them in the jeep yet. another thing i suggest doing is replacing the coil strip when you do the plugs. they are suppoused to only last about 70k and range from $80 (advance) to $120 (mopar from internet) good luck

I'm still running with the platinum 4's and it's been over 30000 miles since I replaced them. I check them every oil change and they are as good as new after I clean them up.

copper has a better spark performance than platinum. however, platinum lasts longer. iridium has the best spark and longest life, but they cost 8x as much as copper and 4x as much as platinum. (personally i think bosch platinum plugs are garbage)

Iridium "A platinum group metal, iridium is white, resembling platinum, but with a slight yellowish cast. Due to its extreme hardness and brittle properties, iridium is difficult to machine, form, or work. Iridium is the most corrosion-resistant metal known. Iridium cannot be attacked by any acids or by aqua regia..."

it's as simple as that... every engine in a jeep is fine with the mopar(champion) copper plugs except the high output 4.7L runs the platinum plugs (but there are suitable available copper plugs to replace them). if you want the best though, spend $80-100 on denso iridium IK16s or IK20s. I'll be using the iridium plugs once i get around to installing my supercharger.

I don't know why everybody won't change to better plugs. I have a 1997 Jeep GCL with 5.2L engine fully loaded, with 325000km. I've replaced my plugs with "Bosch Platinum +4" replaced wires with high performance wires, put in a K&N high flow air filter. The jeep runs so much smoother, quick starts, and the mileage is ranged from 25 to 30 mpg depending on speed. If I drive around 60mph I get about 28 - 30 mpg hwwy. I love my jeep I bought it when it had 270000 kliks on it. I've even replaced the speakers cause they did'nt work, with Sony Xplodes 220watts in fronts, with Sony Xplodes 260watts in rears, in the inifinity Gold system. Kept the same amp and stereo. Very beautiful sound system now. I can crank it up and not blow anything. Horsepower has increased at least 28%. Very reliable for me and my wife even when 4 wheeling. I am the 2nd owner of this Jeep and its my first due to the consumer guide ratings. I hope more people out there are enthused about their jeep as I am. I had one major/minor problem the rear end whined but for $400. I got it fixed at my local garage, this included new e brakes, 2 - lm603012 Bearings, 2 - lm603049 Bearings, Lucus gear oil and labor of $180. I have some other locals that own jeeps, 1. with 1995 Jeep sport has over 900000 kliks and her only problem she had to replace the tranny about 6 months ago other than that regular maint. sched and thats it. the other has over 700000 kliks and no problems. So why the longs faces about Jeeps

May I ask you about the "high performance wires" you've got? What are they? Mopar?