Ive noticed a lot of posts on here that say to run champion plugs. I run bosch something or others. Does it make a big difference?

 

YES YES YES... I used to run bosch platinum 2 and recently switched over to champion spark plugs... Definitely can tell a difference in idle acceleration and over power... Will never go back to anything else...

 

Depends, some years seem to run better with the ngk and others the champions, just do a bit of reading and most of those threads will show why/which is best for your year

 

Platinum tips tend to last longer, copper is a better conductor.

 

I don't like Champions. I have not had good luck with them. Too many defective.

I normally use NGK Platinum.

 

yea i put the bosch plugs in a few months ago and it didnt seem like it made a huge difference in performance, the old plugs were way over due to be replaced, and now im getting a knock, lopes a bit too . rock auto has the rc12ecc plugs for $1.70 so id be crazy not to try them. thanks

 

Hmm, interesting. In my 89 I switched from virtually brand new bosch platinum to Champion Coppers, didn't notice a difference whatsoever.

 

Like a thread said earlier i also depends on year i have a 97 ZJ 4.0 and its been nothing but golden after changing out the bosch doubles to champion... Besides to me unless you have a souped up engine its pointless to buy anything but the champions

 

I changed out my plugs when I first bought this xj over a year ago, plugs were ngk's iirc and changed them over to champions....

and I could tell a difference, steadied out the idle very noticeably...

EDIT: had some reflection I think the plugs were autolite

 

+1
All they have to do is light off the charge and continue to do so reliably for an acceptable period of time. Coppers might get you 30K, double platinums about twice that.
Single platinums are bad news in the waste spark systems (00,01), other than that there's nothing a $7.00 plug can do that a $2 plug cannot.

 

Amen lol

 

there should be info on the underside of the hood in reference to what plugs your XJ takes. I use champion and have had no problems.

 

I tried the Bosch Platinum plugs in my 98 and it ran like crap. I replaced them a couple days later with Champion and it ran perfect.
BTW, They in stalled Champion in the Jeeps from 99 and older and NGK in the 00-01. But our 4.0 will run perfectly fine no matter what year with both Champion or NGK.

 

I'm running NGK and love em'

Can't go wrong with champion though

 

Yes, the waste-spark ignition. Actually, RC12ECC were the factory fill on 2000+, but dur to longevity issues with the distributorless ignition Chrysler recommended they all be replaced with NGK ZFR5N. Outside of those years, NGK or Champion coppers is a matter of personal preference (or budget).

Fancier plugs have a few issues with frequently not being in the correct heat range and causing problems down the road. You'll find a lot of crap like Bosch +4 and E3 things working fine on Day 1, but a few months later it's misfire land. I don't see the point in running $9 plugs and leaving them in for 3 years when you can change $3 plugs annually. Most 4.0s probaby have enough issues they'll kill the fancy plugs long before their time, anyway