I like NGK's. Every NGK plug I've ever pulled from the box was correctly gapped. Definitely can't say that about Champions. However, they are sometimes difficult to find for American trucks. In these cases, I use Autolites.
I definitely wouldn't waste any money on platinum plugs unless the manufacturer calls for them.
I use champions, with a brass terminal distributor cap (aluminum terminals are a hidden problem waiting to happen) along with a msd-6a ignition box. Check and re-gap the plugs every 75,000 miles or so.
...a well prepped, well driven, vehicle should do well in any terrain, including the highway.
Carburetors became obsolete during the last century... do what ever it takes to get fuel injection...It makes bigger grins off road.
Good 'ole (and cheap) Champion Copper Cores are in my Jeep. Runs great!
-Max Black 1996 XJBuild Thread: My Maine-iac XJ part deux
4.5" lift of assorted brands, 33x10.5 KM2s on D-Windows, JCR rear bumper, Nates Slimline w/Champion 8k winch, custom half doors, roof rack, and tire carrier, Maine Woods dents and pin striping, and various other cool things. www.maine4x4.org Maine Jeep Club Member #1 Firefighter Jeep Club Member Black Jeep Society Member #163Survivalist Jeep Club Member #14
I'm throwing in my vote for Champion truck plugs too. I've tried everything from them to the most expensive 4 tip platinum plugs you can buy and I've always gone back to Champion's. I threw a set of Bosch Platinums in the garbage the day I bought them because my Jeep wouldn't run worth a crap. The Champions just seem to run so much better in my motor, never had one problem.
I used to own a saturn and am a member of a forum for saturn enthusiasts (let the flaming begin, i know...). Everyone over there hated bosch platinums like the plague. Equated in usefulness to the turbonator. NGKs seemed to work well for my N/A 4-banger that I had.
My '09 JK comes stock with platinum plugs (according to the manual), but since I am installing a RIPP Modifications Supercharger, their kit comes with NGK IX Iridium plugs one step colder than stock. I was looking for better spark plug wires and decided to purchase the MPG Plus Spark Plug Wires by Granatelli for the JK. They are "0" resistance wires and suppose to deliver more spark to the plugs. I have a concern that the coil may prematurely fail due to the zero resistance and need a lead on a high performace coil to replace the stock one. Can't seem to google one on the internet????
I know the newer (01+ maybe) 4.0's have coil on plug. It wouldn't surprise me if the V6's in the JK's did too, but I have no idea. You've done your research/know what you're talking about, right? I only say that 'cause I know someone that went to buy plugs/wires/coil for his TJ, only to find out that he didn't have them . That really threw him for a loop.
I've used Denso Iridium plugs in a SC 3.2 MB motor and noticed a fairly substantial difference. If they make them for the Wrangler, i'll throw them on when the time comes. I also changed the stocke wires to Magnecor 8.5mm - --pretty nice.
"It is the spirit of men who follow and of the man who leads that gains the victory" ~ George S. Patton
Libertys might not be the most popular jeep for trail riding because of the IFS, but I try anyway...
That said, I need to replace my spark plugs and I was looking for the best spark plugs I can get. Whatever came with my jeep are still in there at 55k and I am starting to feel the engine not running as smooth as it used to.
I read through the thread and you guys seem to like Champion... but should I go with Platinum or Iridium? There is a $6, Iridiums being more expensive. Thoughts?
Any other tips would be appreciated, I want to get the job done well and right the first time.
Edit: Also, I am getting many mixed results as to the gapping for my vehicle? The spark plugs say do 0.035, under the hood says 0.040, and haynes manual says 0.045? What gives? Who should I listen to?
I don't know what is best for a 2.5L or a 4.2L, but I know from experience with my XJ and LJ that the 4L loves NGK copper plugs. Just the regular NGK copper, not the platinum.
I once tried some fancy Bosch platinum 4 prong plugs in my XJ and it ran terrible (no low end torque). The stock plugs (Autolite I think?) are OK. Boche terrible. NGK cooper are by far the best for the 4L (idles smoother, same midend and highend torque as the other two plugs I mentioned, but way better low end torque and smoother running at lowend).
For the 4L I've found NGK are the best. The regular cooper NGK.
NGK also worked best in my motorcyle. I'm really an NGK fan after trying Champion, Autolite, Bosch, and NGK in various engines.