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I finally managed to change my spark plugs today. Thanks to the advice of some of the people on here, I went with the copper Autolite A103s gapped to ~.055. For the last 20,000+ miles I've had Bosch Plat/Irid +4 and by the time I changed them out my car just felt so overly lethargic, like there was hardly any power and like it constantly struggled to move. So I put these new ones in and although it's only a small difference, I definitely notice an improvement in my car's pep and get-up-and-go. It doesn't feel as sluggish as it did.

I'm waiting to see if there's any real difference in fuel consumption, but so far, after taking a 150 mile freeway trip it appears to be roughly the same.

Changing them out was super easy though. I ended up doing it at night with almost no light and it still was no issue. Just a little flashlight.

This vid was a big help:

 

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Ar103

I just changed out a set of AR103's with 34,000 miles on them. They were originally gapped at .055 and are now between .058 and .060. The car was starting to stumble intermittently so I figured it was time to change them. When I installed these a while back I had noticed the OEM plugs were burning hot with a white tip. I saw this sticky and took the recommendations. I am glad I did. The car ran fine with the ar103's. Here is a pic of one of the ar 103 plugs I removed the other day . Interesting how the tip has been burned off at a slant. They all looked like this.
 

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Just installed AR103 capped at .055 yesterday and ever since then my car is very hard to start
Once started runs amazing. It is a 2007. Any thoughts?

Sent from my SM-G950U using Tapatalk
 

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Ignition Coils

I will definitely use The 103's on my next tune-up. I'm looking at replacing the coils with Accel Super Coils. They claim to produce 15% more spark energy. With that in mind, do you think the 103's could be gapped to .060 for maximum benefit? Or would it make sense that the .055 gapped plugs would last longer?

Thanks for the info!
 

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Just installed AR103 capped at .055 yesterday and ever since then my car is very hard to start
Once started runs amazing. It is a 2007. Any thoughts?

Sent from my SM-G950U using FF Mobile
Chances are it's harder to start either because of the larger gap or the colder heat range. If you don't have a set of AR104s handy to swap in, it's cheaper to try closing the gap to stock, first. If that doesn't help, you can always open it up again, and/or buy a set of AR104s and see if that helps.
 

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Colder heat range wont cause a harder start , The heat range of the plug doesnt come into play till the engine is running and up to temp and there is a LOT that goes into choosing proper heat ranges , its a balance of cool enough for your Mods / build but hot enough so it burns off and keeps the plug clean

Gap can and 85% of the people that use the AR plugs gap them the conventional way going straight in horizontal to the surface of the plug , the AR plugs need more of a 45-60 deg , remember you setting to 2 closest points and thats no longer on the top of the electrode but more to the side

On my dyno we were the first to test the AR ( Autolite Racing ) spk plugs for Autolite and it went in a Magazine wrote by David Vizard , gained 13hp to the wheels with a V8 Chevy Engine Dirt Late model over 6-7 other brand and heat range plugs

Tom
 

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In the late 80's and early 90's I was an Engine Systems Specialist for all makes and models, was replacing spark plugs in everything 60 hours a week, saw some crazy stuff. Fast forward to 2018, that is no longer my occupation and my 2005 ZXW is approaching 50k miles, so I'd like to replace the plugs this spring. After spending 20 minutes reading through these 23 pages I have to be honest and say I'm more confused than ever, lol. Simple question for the knowledgeable... what is the proper, basic copper, Autolite and NGK equivalent plug, for a stock 2005 ZXW 2.0 Duratec? (not looking to tweak anything) RockAuto lists 104 and 4177 and that contradicts many numbers listed in this thread.
 

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I highly recommend the Autolites AR103 or if your bone stock and not adding anything the Autolite AR104 , you can buy the 103/104 non AR but the AR is better as it has the cut back wire

Biggest problem is people try to set the gap in the conventional way and that cant be done with the AR plugs you have to actually set them at an angle , remember you adjusting the gap , the distance between the 2 points , with the wire cut back it changes how you gap the plug

I would NEVER run NGK in my Focus or my Customers Foci

Tom
 

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I highly recommend the Autolites AR103 or if your bone stock and not adding anything the Autolite AR104 , you can buy the 103/104 non AR but the AR is better as it has the cut back wire

Biggest problem is people try to set the gap in the conventional way and that cant be done with the AR plugs you have to actually set them at an angle , remember you adjusting the gap , the distance between the 2 points , with the wire cut back it changes how you gap the plug

I would NEVER run NGK in my Focus or my Customers Foci

Tom
After reading so many contradicting posts I finally broke down and went with the first pages recommendation and bought the El Cheapo 103's and left them at stock gap .60, when changing them I found my old plugs(which turned out to be Autolite XP 104's looked ok) swimming in oil, after a quick search I figured I needed to replace my valve cover gasket. I went with the Fel-Pro VS50639R1 the "Improved Design" all the gaskets were blue silicon. Some oil leaked in to the cylinders when I was swapping out the plugs which caused a little smoke out the tail pipe. I also changed the oil & filter and fuel filter too. It still had a issue taking a bit longer to start after it has just been running. But that may have cleared up today but I will not know for sure until a few days have passed. I can say that the car feels more "peppy" I will also update my mileage if I notice an improvement. Can or should I clean these 104 XP's up and try to reuse them?
 

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I highly recommend the Autolites AR103 or if your bone stock and not adding anything the Autolite AR104 , you can buy the 103/104 non AR but the AR is better as it has the cut back wire

Biggest problem is people try to set the gap in the conventional way and that cant be done with the AR plugs you have to actually set them at an angle , remember you adjusting the gap , the distance between the 2 points , with the wire cut back it changes how you gap the plug

I would NEVER run NGK in my Focus or my Customers Foci

Tom
Thanks for the reply. One more thing, I do 2-mile short trips twice a day at 7am and 5pm in addition to normal driving, so I'm wondering if that should influence my decision to run a standard copper plug or another platinum like it originally came with.
 

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I highly recommend the Autolites AR103 or if your bone stock and not adding anything the Autolite AR104 , you can buy the 103/104 non AR but the AR is better as it has the cut back wire

Biggest problem is people try to set the gap in the conventional way and that cant be done with the AR plugs you have to actually set them at an angle , remember you adjusting the gap , the distance between the 2 points , with the wire cut back it changes how you gap the plug

I would NEVER run NGK in my Focus or my Customers Foci

Tom
Why wouldn’t you run NGK? I’m just wondering because I changed my plugs in my 09 SE and the engine vibrates at 1500-2000 rpm now. Tried ACDelco’s and they do the same thing. Should I try Autolite 104 next?
 

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Why wouldn’t you run NGK? I’m just wondering because I changed my plugs in my 09 SE and the engine vibrates at 1500-2000 rpm now. Tried ACDelco’s and they do the same thing. Should I try Autolite 104 next?
Denso's for d-tech's...
 

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Why wouldn’t you run NGK? I’m just wondering because I changed my plugs in my 09 SE and the engine vibrates at 1500-2000 rpm now. Tried ACDelco’s and they do the same thing. Should I try Autolite 104 next?
You tried AR103 or 103 autolites ?

Tom
 

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I am going to be installing the AR103's in my 06 Focus this weekend when i do the valve cover replacement. Is there anything I should know when I put these in or is there anything I need to do tuning wise as well? This will be the first plug change as far as I know since I got the car with 45K on it now with 155K.
 

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AR103 vs 103

I had AR103's in the car gapped to 0.050" with about 20,000 on them. My old engine had some rough miles on a bad timing chain. I swapped the used plugs over when I went to a 2.5L, but today I decided it was time to try some new plugs.

I gapped a new set of normal 103's to 0.055" and found that the car was a tad bit smoother to drive, but kinda feels like it lost some power. does that make sense?

The AR103's had not gotten much wider which makes me think that I replaced them too early. especially since the new plugs didn't really result in more 'seat of the pants' horsepower.

Thinking to gap the new plain 103's to 0.060" and rolling with them...
or would it just be better to put the AR103's back in until I can order a fresh set?

running cams, header, full 3" CAI, throttle body, and 93 octane tune.

bonus question.. would upgraded coil packs be worth my time?
 

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I had AR103's in the car gapped to 0.050" with about 20,000 on them. My old engine had some rough miles on a bad timing chain. I swapped the used plugs over when I went to a 2.5L,
If you now have a 2.5 then the Autolites AR103 .750 reach will be .250 to short , Get a set of Motorcraft SP463 there .980 reach they will run better

The 2.5 head takes a .980 reach plug

Tom
 

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[
If you now have a 2.5 then the Autolites AR103 .750 reach will be .250 to short , Get a set of Motorcraft SP463 there .980 reach they will run better

The 2.5 head takes a .980 reach plug

Tom
I guess this is a better thread to ask this on..
Is there a .980 reach copper plug? I’d prefer the shorter life/ cheaper cost/ better performance
 
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