NGK G-Power platnium
*****Disclaimer: My WJ is not stock. I have a tuner, intake and exhaust that may affect this review.
So I have seen a lot of debate over spark plugs with the 4.7L. I re-gap my plugs or change them every 25k or so. I couldn't decide if I wanted to keep with the champion's or not. I figured I'd try something new. I went with the NGK G-Power (Single Platnium) for my 02 wj.
Upon taking my plugs out they looked great, but the gap had grew to about .045. I didn't NEED to change them, but I did anyway. They were all correctly gapped from the factory, and yes I checked.
Right off the bat it seemed to run a bit smoother, and I liked that! I now have about 1k miles on them and my gas mileage has went up by 2mpg!! I was shocked. This is the best mileage I have ever had with the WJ since I started adding tons of weight to it.
I would def recommend to anyone that can't decide what plugs to go with.
I also helped RYANSWJ put the same plugs in his, with only a K&N intake and he says that it's a much smoother running engine now. He hasn't looked at the mileage though.