2017 GT350R spark plug change

[GB17shelbyGT350R]

* To be clear, No, I am not having any issues with this car. And Yes, 22k miles isn't Fords suggested spark plug replacement interval change. But in my opinion a 9+ year old car, Why the F*ck not change something that's $50 and an hour to change......now let's drive for another 9+ years with no plug worries.

** Informational Post only, you must follow your own maintenance schedule**
Sharing my experience to help anyone else looking for more info on plug part numbers, plug gaps etc.

I have a 2017 Shelby GT350R GB with 22k miles. I've owned since 2020, it's been such a great car. I have changed all fluids over to Amsoil the week after purchasing, rear differential, trans fluid and engine oil. With that said, I enjoy maintaining my car, whether it's fluids, brakes and brake fluid etc. I figured I hadn't done plugs, something cheap and easy to change out.

I removed the rear passenger plug first to find I have Iridiums CYFS12Y (not sure what SP #) but I'd imagine SP509 comparable.

I did some looking prior (didn't remove a plug first) and purchased some Ford Motorcraft Sp-548 Platinum plugs as most forums or posts referenced them. These plugs come around .052 gap out of the box. My Iridium plugs removed were around .054- .055 on gap. (.02 gap change from New)
I contacted a few reputable Shelby mechanics and they assured me that the SP 548 platinums are good to go but to gap them around the tighter spec of .039. There was supposedly an update on the 19+ to have the gaps around .039 on a N/A car. So that's what I ended up doing, installing the SP548 plugs gapped at .039-.040 (as close as I could get). I installed and torqued down, 12-14 lb ft is recommended from what I've read and what's printed on the Ford Motorcraft box.

Pretty easy job and for around $50 for all 8 plugs, she will be good to go for another 9+ years or 22k miles.
I have since started the car up and letting it idle for some time, so far no weird sounds or issues. I don't expect to have any issues but I will update if that changes.

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[Gilberjj]

I wonder when I should do mine….?
2016 gt350r with 4k miles

 

[robvas]

Those had a lot of life left

 

[CorralesR]

I wonder when I should do mine….?
2016 gt350r with 4k miles

Sounds like you have lifetime plugs!

 

[WItoTX]

Where did you find 8 SP548s for $50?

I was today years old when I learned the 18-20 had a tighter gap. Interesting. Now I get to learn why today.

 

[DCShelby]

Yes changing plugs on a 911 is an adventure of sorts. Worst is the 991.2 where you take the intercooler plumbing off, the rear bumper and other stuff. Rear wheels too.

 

[bKennedy]

I changed mine at about 60K miles and they still looked good. I think it's a good idea to change them after 5 years, no matter what the mileage, just to ensure that they are not getting seized into the head, although this may not be a valid concern anymore. Make sure you read the information on the box as my plugs recommended you do not put any anti-seize compound on them. I used NGK Iridium plugs for the replacements.

 

[honeybadger]

Spark plugs are such cheap insurance - I always change em' much earlier than recommended as well.

On a side note, looks like cylinder #3 is burning a bit of oil - but doesnt look overly bad. how much oil are you going through every 1k miles?

 

[GB17shelbyGT350R]

Those had a lot of life left

Thanks.

Where did you find 8 SP548s for $50?

I was today years old when I learned the 18-20 had a tighter gap. Interesting. Now I get to learn why today.

Amazon Link below

https://a.co/d/0420fwkf

Not too bad. My Limited Powerboost plugs were more expensive for 6

 

[GB17shelbyGT350R]

Spark plugs are such cheap insurance - I always change em' much earlier than recommended as well.

On a side note, looks like cylinder #3 is burning a bit of oil - but doesnt look overly bad. how much oil are you going through every 1k miles?

I'd say about 1/2 quart per 4-5k miles. I've been pretty good at letting her warm until 170+ before going over 4k rpms. A trip to the tail with her was fun but did notice a drop on the dipstick when I returned. Holding those high RPMs in the mountains was alot of fun 2nd -3rd gears were definitely the sweet spot with very very minimal braking! Definitely a bucket list checked off

 

[GB17shelbyGT350R]

Ran across this website as well has a buyers guide for spark plugs.....looks like Iridiums or platinum can interchangeable for multiple years of the Voodoo 5.2.

Decent pricing as well for anyone needing more options.

https://www.opmustang.com/store/p12...K_PLUGS_OEM_MUSTANG_GT_-_GT350_-_GT500.html#/

 

[honeybadger]

I'd say about 1/2 quart per 4-5k miles. I've been pretty good at letting her warm until 170+ before going over 4k rpms. A trip to the tail with her was fun but did notice a drop on the dipstick when I returned. Holding those high RPMs in the mountains was alot of fun 2nd -3rd gears were definitely the sweet spot with very very minimal braking! Definitely a bucket list checked off

That's not bad at all. and I always noticed more oil burn whenever I had more engine braking - so spirited driving/track use makes sense. I gotta' drive the dragon some day!

 

[WItoTX]

Thanks.


Amazon Link below

https://a.co/d/0420fwkf

Not too bad. My Limited Powerboost plugs were more expensive for 6

Someone did an analysis on real vs fake, and Amazon was the #1 offender. Not to poopoo your purchase, but just keep it in mind if you notice something out of the ordinary or get a CEL in the future.

It's annoying as hell that we can't trust online vendors to supply genuine parts, but such is the world we live in.

 

[GB17shelbyGT350R]

Someone did an analysis on real vs fake, and Amazon was the #1 offender. Not to poopoo your purchase, but just keep it in mind if you notice something out of the ordinary or get a CEL in the future.

It's annoying as hell that we can't trust online vendors to supply genuine parts, but such is the world we live in.

Yeah this would suck. I've seen a lot of people online, even questioning buying Ford Motorcraft from Mustang performance websites? I guess if counterfeit is a thing, unless getting them directly from your local Ford dealership, you're taking a risk at any counterfeit? Whether it be spark plugs coils, oil filters, etc? Exactly, sucks that the counterfeiting has went as far as automotive parts for OEM distributors. But I guess that's the world we live in nowadays. Looking at the spark plugs from the Ford local dealership, I would have paid another $10 for all eight, maybe I'll just stop by my local Ford dealership. Grab a handful of extras just in case

 

[edunn14]

Any issue getting to any of them, or upon removal? I am approaching 37k on my 2018 and I'm sure it would help me sleep at night to swap them out. Hoping they aren't seized and/or I make a "now the head/engine needs to come out" mistake. I haven't read of any issues like that but curious on your take having done it recently.

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