Ok - dopey question but will ask anyway....

Have 03 TJ and know it has three normal and 3 other spark plugs - maybe platinum??? Anyway just wanted to know if anyone knows if the normal ones can be replaced with the good ones... thought this may improve performance a bit but will it then mess with the spark gaps etc and will it need to be adjusted?

Also does anyone know the costs of the good ones compared to the normal ones?

Is this even really worth doing? It is just an idea - maybe there is a reason why only 3 of them are the god ones to start with?

Any info would be great...

of course you can replace them. y are there 3 and 3? i replaced mine, runs better. it will improve performance and you shouldnt need to do any adjusting. if ur misfiring replace the coil and dizzy. prices vary. normal ones are like 3 bux each. top of the range can be up 25 bux each. its fully up 2 u. but still change them so there arent different plugs inthere. make em all the same. get 6 new ones and throw them in :D

Yes in 3rd gen V6 the front 3 are normal spark plugs and the rear 3 are platinum ones. The reason they are like this is because the rear 3 are more difficult to replace, you have to remove the intake manifold to get to them.
I think it would make stuff all difference replacing the front ones with platinums, they'll just last longer thats all. From memory the rear platinum plugs only have to be replaced once every 100,000km.

All true.... Platinum are expected to last for 100,000km. The difference is the platinum tips. Higher quality = longer lasting and probably higher standard of spark. Would be awesome to have six PT's in but costs are usually what stops everyone doing it. I did in mine though, cost me about $120 for the plugs and did the labour myself. Pretty easy job, just time consuming. Hope this helps. :D