So I've spoken with two mechanics. One on the Mopar payroll, and one who isn't. Both said not to mes with aftermarket plugs and wires, just stick with mopar. Can anyone verify this data as the best advice?
Joe n Jules Merenda
2010 Wrangler Unlimited Mountain
Bone stock save the K&N but I cant wait to trick it
1998 Cherokee Sport
Chrysler doesn’t make their own spark plugs, in fact I think they are made by Champion. Most of the time mechanics like to keep with parts they get from the dealer because a) warranty and fitment can be assured and b) they don’t want to take the time and/or be responsible for researching an alternative that may be as good or even better (or cheaper).
IMO, there is no reason to buy parts from the dealer if they can be purchased somewhere else. There are always parts that will work that are sometimes cheaper, sometimes better and sometimes both, you just have to do your homework.
You don't say year and engine type but here is my $.02 worth.
the standard plugs be they OEM or brand x will perform just fine in a stock engine so long as the heat range is compatible and will last about 50k before they start to degrade.
Platinum or iridium tip will last much longer and might improve performance slightly.
I would stay away from so called performance plug [3G] and plugs with multiple ground electrodes the are just hype in my experience and not worth the extra money.
I have had good luck both NGK and Bosch platinum and a real nightmare with G3 when the electrode broke off and was digested by the engine fortunately it chewed it up and spit it out with no damage to the engine could have been worse.
Some vehicles can be fussy about aftermarket parts. Some aftermarket parts are not made within the tolerances required for said vehicle. My truck as an example does not like anything but OEM plugs or it runs like crap. I am not too sure about the Jeep yet. I always go with tried and true products to save hassles down the road. Unless several people here can tell you that brand X plug works well in your 3.8 then I would use Mopar plugs etc. as you know those work already.
Stick with the 7440 Champion double platinum’s on your 3.8L its oem and actually a good price if you buy them at AutoZone not to mention offer the best performance you are going to get and be safe doing it. I ran the Autolite Iridium’s in mine for a while and it didn't throw codes it also wasn't running as good as it did with the OEM Champions either. In fact just last week I replaced the Autolites with the factory Champion 7440'S from AutoZone. I only had 25k on the Autolites but, the gap was way out. I had some plugs that were as much as .070 not really impressed for a 8 dollar a piece plug. It was less than 25 bucks with tax for the OEM Champions. Wire wise I use the Dura last ones from AutoZone. Most will tell there is nothing to gain with fancy wires are plugs when it comes to the Jeep 4.0L or 3.8L very easy going engines. 3.6L might be a different story can't comment on it. They are less than 30 bucks and have a lifetime warranty so you never have to buy wires again. A few things to remember. Check the gap on the plugs this is probably the most important because I found my new ones to be off a little bit. Gap is .050. also Champion coats all there plugs with a type of anti seize already so do not put any because you will over tighten them being the plugs don't have a washer on them. 12ft is the torque for the plugs I didn't do mine like that just hand tightend and turned just a smudge. It’s not a hard job but, plan on it taking a few hours to do it right. Left side is very easy and will make you think it’s a cake walk but, the right side can be a bugger with both wires and plugs. Be careful with the plug wire holders they will break if you yank on them or move them to much especially with age and heat they get under there. Wear long sleeves if you can because I can guarantee some cut arms.
Thanks guys. Bubba, its the 3.6 in my 2010. I put NGK platinum in my '98 Cherokee Sport (4.0) and they seem fine. Was also thinking Bosch Platinum as well. Any thoughts on these?
I have used Bosch Platinum in the past in another vehicle and I did not like them. The car I had them in ran great at first then I would notice the idle would get a little rough after a year or so. I have been using the NGK plugs for several years now and they work great.