My spark plugs... ever changed?

[tjkj2002]

They do not REQUIRE them, but will run fine with them. To cut costs, every so small (S.M.ALL), Chrysler used copper plugs instead of Platinums in our Jeeps. My former Avenger and Cirrus came with Platinums, my Vibe has platinums... This was also the reason, cost cutting, there is no weather stripping on the windshield or other windows besides the moon-roof.

Actually the 4.7,by design,requires cooper core plugs to run at peak performance.Same goes for the Viper V10 as most high end sports cars use copper core plugs to gain peak performance.

From the slight design difference in the 3.7 a platinum plug is okay to run.I always got better performance with copper core plugs until after reaching 12:1 compression ratio,then even platinum's didn't do any good either and had to run Iridium's.I ran 11.5:1 in my SBC in my blazer and could only achieve max power(475HP,513lbs-ft of torque) with a good 'ol set of copper core AutoLites,it was over 30HP versus platinums on the dyno(where breakin and tune was done),got the printouts somewhere in my garage back in SD.

 

[jnaut]

Update:

Did my change today with the new Bosch Platinum Plus'. I have to say that changing the plugs was way overdue. Jeep had been running rough and I barely noticed it. Now the thing runs like a freakin' sports car. Idle is as smooth as a baby's bottom. Acceleration is smooth and even. Whole thing seems to have more get-up-and-go. On my test drive I felt like I was driving a new vehicle.

I even felt five years younger, my crows feet are mostly gone... and my hair? I'm pretty sure it's thicker and fuller.

As for the controversy on the Bosch Platinum Plus plugs, I'll just have to wait and see. They were only $2.99 a piece, so if I suspect they're giving me problems, I'll switch to Autolite or some other brand. From what I'm reading between the lines on Idaho08's warning, is that the people that are complaining are using the expensive +2, +4 and Iridium plugs. I'm not using those, so hopefully I won't see any issues.

 

[Idaho08KK]

From what I'm reading between the lines on Idaho08's warning, is that the people that are complaining are using the expensive +2, +4 and Iridium plugs. I'm not using those, so hopefully I won't see any issues.

+1^ The +2 and +4 are the ones that we normally see causing the misfire issues.

 

[Powerslave]

My MPG is almost 20 at about 19.8 with these plugs. A little better than the 16/17 I was getting. I had the A/C on for one trip, so it may have been about 20 or better without using it for a 30 mile trip... Right now, with 10 gallons, I got 198 miles, with A/C on for about 30 of those miles.

We can all argue just a plug change helped, but, I have always seen gains using better plugs. I will try the diamond fire plugs, and see what I get.

 

[Dave]

My MPG is almost 20 at about 19.8 with these plugs. A little better than the 16/17 I was getting. I had the A/C on for one trip, so it may have been about 20 or better without using it for a 30 mile trip... Right now, with 10 gallons, I got 198 miles, with A/C on for about 30 of those miles.

We can all argue just a plug change helped, but, I have always seen gains using better plugs. I will try the diamond fire plugs, and see what I get.

Powerslave.....yeah, my results were the same as yours when I did my plug change. When I pulled #1 plug at 30,000 miles it was well worn. I replaced mine with the OEM NGK's (ZFR6F-11-G) gapped at .040 like it says on my 05 vehicle emissions sticker under the hood. I noticed an immediate difference. (yeah....yeah.....I know I used the NGK's) Point is though, that new plugs made a BIG difference. From what I have seen here I don't think the copper core NGK's last that long before the electrodes wear.

I think the trouble with plugs is that they wear over time and you get used to it so don't notice it and then you change them and WOW......

I am not much into fancy plugs, but I would be interested in your opinion of the diamond fire plugs if you try them. For my next plug change I was thinking of the Autolite double platinums.

Dave

 

[jnaut]

Powerslave.....yeah, my results were the same as yours when I did my plug change. When I pulled #1 plug at 30,000 miles it was well worn. I replaced mine with the OEM NGK's (ZFR6F-11-G) gapped at .040 like it says on my 05 vehicle emissions sticker under the hood. I noticed an immediate difference. (yeah....yeah.....I know I used the NGK's) Point is though, that new plugs made a BIG difference. From what I have seen here I don't think the copper core NGK's last that long before the electrodes wear.

X2 on this. Please note that I'm being very careful to not attribute my smoother running engine to the Bosch brand or the platinum type. I'm assuming that my improved performance is due to the fact I changed the plugs, period (see photo at top of thread). I'm guessing I'd have seen a marked improvement had I stuck a set of OEM NGK's in there as well.

The only way I'll know if these Bosch Platinums are any good will be over time. How fast to they wear out... corrosion issues, misfires, sudden poor performance later down the road. I'll be happy to report any results the I can attribute directly to the Bosch Platinums.

 

[jnaut]

copper core plugs until after reaching 12:1 compression ratio,then even platinum's didn't do any good either and had to run Iridium's.I ran 11.5:1 in my SBC in my blazer and could only achieve max power(475HP,513lbs-ft of torque) with a good 'ol set of copper core AutoLites,it was over 30HP versus platinums on the dyno(where breakin and tune was done),got the printouts somewhere in my garage back in SD.

I'm real nervous about sticking my toe into this one, but... I'm no expert on this (but I read other people who are), 12:1 compression ratio? That's like the highest ratio you can run on pump gas, requiring like 105 octane. Then 11:5 you start to need racing gas? How were you doing this?

 

[offrovering]

i dont think i changed the plugs on my wifes liberty until close to 80k, original factory came out. put autolite platinum in, from recommendations here, seems to run great on them.

my land rover runs 100x's better on copper plugs, its a 4.6. a high end plug doesnt necessarily mean your specific engine will run better on them. usually higher end plugs just last longer, not necessarily perform better.

 

[tjkj2002]

I'm real nervous about sticking my toe into this one, but... I'm no expert on this (but I read other people who are), 12:1 compression ratio? That's like the highest ratio you can run on pump gas, requiring like 105 octane. Then 11:5 you start to need racing gas? How were you doing this?

11:1 would be the highest I'd run with 93 octane premium.My '84 SBC Blazer was at 11.5:1 and ran half 93 octane and half CAMII race gas(116 octane).The '75 Cutlass I had with a a well built 350 Rocket was at 13:1 compression and only used 100% CAMII or AV gas.My buddy Russ is running a 640 cu in Wedge motor in his Demon,over 900HP,9:1 compression using 93 pump gas,my other buddy Rodney is running a 555 cu in Rat motor in his Nova,600+HP,9:5:1 compression ratio running 93 pump gas.They opted for the lower compression and more cubic inches for reliability since they both are street driven.

 

[moparman]

i dont think i changed the plugs on my wifes liberty until close to 80k, original factory came out. put autolite platinum in, from recommendations here, seems to run great on them.

my land rover runs 100x's better on copper plugs, its a 4.6. a high end plug doesnt necessarily mean your specific engine will run better on them. usually higher end plugs just last longer, not necessarily perform better.

The Land Rover engine has some ancient DNA. http://en.wikipedia.org/wiki/Rover_V8_engine

 

[Powerslave]

Yeah, I was going to buy one (Land Rover) for $2000.00, and needed some work, Engine work. I found out it was a Buick motor, and could have fixed it with little effort, hell, even changed it out. I just did not have 2K at that point in time...

 

[Dave]

The Land Rover engine has some ancient DNA. http://en.wikipedia.org/wiki/Rover_V8_engine

That's a real neat history.

A friend has an old rover and I helped him working on it a couple of times and that's when I discovered it had a GM engine but I had no idea of the actual history of it until you posted that link. Thanks for the info.

Dave

 

[offrovering]

correct ancient and if you ever pop the hood of a rover youd see how ancient. pretty damn easy to wrench on yourself, and usually doesnt take fancy stuff like new age engines. I run cheap rotella t 15w40 oil, and copper plugs. issues come up with you need a genuine part.

 

[KJ zGal]

You actually waited that long to change the plugs? Mine came out at 16k in the WK

When we changed my KJ's spark plugs at 111k, my brother told me the NGKs weren't stock. So knowing they apparently WERE stock...I guess spark plugs can last a longgggggg time. No wonder they were like down to nothing when I took them out...

 

[jnaut]

When we changed my KJ's spark plugs at 111k, my brother told me the NGKs weren't stock. So knowing they apparently WERE stock...I guess spark plugs can last a longgggggg time. No wonder they were like down to nothing when I took them out...

It's possible the OEM (ngk) plugs were merely replaced with a new set of same. Given how mine looked at 73k, and I still have no *proof* that they were never changed (or were changed for that matter), I'd imagine yours would be hosed completely at 111k. Let's put it this way, if my plugs were changed and they were as worn as they were in the picture, then yours should have been a ceramic nub rattling around inside your engine.