ok first things first. DO NOT use bosch in mopar! not made for it dont work good. it really depends what you have done to your jeep and how you drive it. if slightly moded use factory champions. if you do a lot of crawlin and other low gear drivin i would use e3's they work great in everything i've put them in. they increased milage in my 97 limited and haven't fouled yet (check them every oil change). they produce a bigger flame kernal there for burn more of the fuel in the combustion chamber. they also work good with aftermarket ignition boxes.

http://www.e3sparkplugs.com/

 

I'm running Bosch Platinum IV's in my stroker and used them when my motrt was bone stock. No problems ever.

 

x2 with what stryker said.

 

I have run the Bosch platniums for several years without any issues, but I have an MSD 6AI ingnition box. Withthat box, Champions get destroyed in no time. The tip erosion of the champions is evident after only a few months. The high voltage oof the 6AI aslo destroys plug wires in a hurry, I replace my wires every 8 - 10 months because of this. I would not go back to the standard ignition, as the 6AI provide a hugh power increase, and my emissions pass every year without any issues.

 

NGK FTW

 

autolite platinums here also.......

 

That's where the erosion comes from.
(not just champions, but any non precious metal plug.)
Everytime your plug fires the spark take a few atoms of metal with it.
Eventually the gap becomes too wide for the spark to cross causing misfire.

As an added note that is one reason why resistor plugs were invented.
Most people think it was because of radio interference. And that IS a side benefit.
But the resistor was invented to help plugs last longer.
When a non resistor plug fires, the spark may "bounce" back and forth a few times.
(between the ground and the electrode.)
Each time taking a bit more metal with it.
That is what causes the static in your radio also.
A resistor plug only lets the spark cross once.
Thus limiting plug erosion AND making it so you can listen to AC/DC without static interuption.
Just f.y.i..