what spark plugs are best?

[mikeny59]

Bosch 4's, last 40k or so, sotp noticable improvement, but that's just me.

'98 4.0 msd wires kn cone only performance mods.

mike

 

[XplodJeepster]

I run them on my 95 xj. i took the chemists opproach on looking at conductility chart call the periodic table.
the only super perfomance gains(?why?) come from installing larger wires...I can say this cause i too ran them on an old ford pickup truck. and installed them with the MSD superconductor wires. and they really put a lil more go in the smaller engines.

I've never had any maint issues with the plat 4's, and I'm making 22 mpg at most driving winding country roads

 

[BEVAN]

Champion Truck Plug #4412

whats in mine.

 

[old_man]

$.89 each Champions

 

[Ron Hyslop]

I'm with Tom

 

[BCParker]

what is the difference between the champion truck plugs and the normal champions?

 

[langer1]

what is the difference between the champion truck plugs and the normal champions?

$1.20

 

[BCParker]

lol- Size, Spark the same?

 

[Bowzer]

:confused1 Copper! :roll:

 

[CartsXJ]

whats in mine.

Same here, been running truck plugs since I've owned it. Took out some very burnt up bosch's, well thats what they looked like. I think the only difference between the truck plug and the regular champion is that the truck plug has a copper outer-better for heat radiating, the electrode is bigger, and the overall heavier duty construction. For me the 50cent difference in price is defiantely worth the extra piece of mind.

 

[53guy]

Well, the way I figure it, the engineers over at jeep know how to design a motor that runs well over 300,000 and is still strong, I think that I will take their advice as far as spark plugs go. So champion OEM for me! Now as far as the suspension engineers go.....i'll just say they had grocery getter in mind when designing it. lol

 

[Bradlybob]

I just pick up a set of Champion plugs and for the heck of it checked the resistance of each plug. They varied from 22k ohms to 73k ohms with no 2 plugs being close to each other. What the heck? Has anyone else measured the plug resistance and tried to match the plugs, or is this really unimportant in a normal stock engine. My guess would be that it really doesn't matter but 51k ohms seems like a big difference. Quality control? What's that?

 

[wacho4]

Never tried platnums in the xjs, but in two other older designed engines (1977 dodge 318 & an olds 307) I did just for the heck of it they ran ok but not very well. I think they only work great on fancier or more up to date engine designs (and german). Having nothing with a fancy or newer design engine, I don't really like em.

Does anybody have any expierience or opinions on this? :
The firepower kit(available thru Quadratec and 4wheel drive hardware and I'm sure others) says you can gap the plugs up to .065 or something like that. Does anybody know if this acually creates much more power in this engine? This seems kindof a pricey kit for just a tune up and high performance coil?

 

[wacho4]

I mean pricey for just the couple horsepower that I would think would be the most you'd get.

???

 

[aeruro]

tried those bosch plus-4s in my 01 xj. they didnt work for me. took it to jeep dealer and first thing he said was who put them plugs in? his expanation to me was that there are 2 types coil rails for 2000-2001 jeep 4.0 engines. the one for plat plugs is hotter and gives out more powerful spark. it ran good again after they installed the regular champ. plugs.