[urezki]

Hello folk,

I am to change spark plugs on my Jeep (2005 Laredo 3.7L). I am confused about which spark plugs i should use.

According to the spec, i should use Mopar SPZFR6F11G plugs (Resistor Copper Plug). But i was not able to find them, instead i bought Autolite AP5224 they are platinum ones.

My questions are:
Is Autolite AP5224 appropriate for my engine ?
Does anyone use them ?
What are the best plugs for my engine ?

Thank you.

[lwg8tr01]

I put in some Bosch double platinums about 2k miles ago and they work just fine. I don't think the 3.7L is as picky when it comes to plugs as the Hemi which needs the copper plugs. There are tons of threads here about what plugs to use, which is better, lots of anecdotal stories about stories of stalling, performance degradation, mileage drop off but they all seem to be non 3.7L specific. Me personally, I get a smoother idle and a about 2 more MPG in the city.

[tjkj2002]

Been running the Autolite double platinums for since 20,000miles(have 70,000 now) in my 3.7 and they work great in the 3.7.Though I do change them every year regardless of miles put on them.

[urezki]

Hm, i looked through this forum finding out this question, but found a lot of meanings, one people say
NGK is the best, other one say Champion and NGK is a crap.

Ok, i will go with Autolite and will see.

[08WKJGC]

Im using the Bosch planinum plugs as well, no issues at all.

[lwg8tr01]

Originally Posted by 08WKJGC

Im using the Bosch planinum plugs as well, no issues at all.

I don't know where this thought that you need to replace the spark plugs with the OEM ones got started. The ECM will adjust to just about any spark plug. I think it confuses peole when they see the "recommended" OEM replacement and mechanically what will work just fine. If you read further MOPAR recommends their own brand of air filter also, does that mean a K&N would'nt work optimally...silly huh? I think it's just an excuse to bicker on the internet.

[maxst2]

Originally Posted by lwg8tr01

I don't know where this thought that you need to replace the spark plugs with the OEM ones got started. The ECM will adjust to just about any spark plug. I think it confuses peole when they see the "recommended" OEM replacement and mechanically what will work just fine. If you read further MOPAR recommends their own brand of air filter also, does that mean a K&N would'nt work optimally...silly huh? I think it's just an excuse to bicker on the internet.

Not true. Its been proven that platinum plugs don't work as well in some applications... I.E. they swapped to copper and rough idle and performance was sorted. Copper is superior in electrical conduction compared to platinum, but doesn't last as long... platinum does last longer...but with less conduction.

They make it OEM for a reason...because its designed to use X part.

[Kaliber35]

I just dropped some NGK platinum cores and have no complaints so far. I have actually even noticed an increase engine performance.

[OGRC10T]

Originally Posted by maxst2

Not true. Its been proven that platinum plugs don't work as well in some applications... I.E. they swapped to copper and rough idle and performance was sorted. Copper is superior in electrical conduction compared to platinum, but doesn't last as long... platinum does last longer...but with less conduction.

They make it OEM for a reason...because its designed to use X part.

I agree with you. OEM is there for a reason. I have noticed that different plugs work better in some applications than others. Platnum does last longer, but are not always the best to use for every application.