Ford Racing (M-12405-35T) 10-17 Flex 3.5L EcoBoost Cold Spark Plug Set

Use to replace my stock plugs at 40k after I got the 5 star tune. This helped stop the little stuttering at idle and the truck runs a lot smoother and cleaner. I got these per 5 stars recommendations as they are high performance. This was the easiest tune up I’ve never done, took me 20 minutes,10 minutes per side. Just make sure to get dielectric grease. I bought the boots but my truck came with a different kind of boot. Only problem is that if one of them breaks or is bad and you need to replace it you cannot buy them individually. Ford doesn’t even sell this part number anymore and you have to special order the spark plug if you need to replace one. The gap is closer is closer to .28 but if you’re tuned that’s ok. Honestly for the price and how fast you get them you can’t beat them, but I did have one go bad and I had to pay $13 to try to find one individually at that point you might as well just buy a new set.

After tuning my 3.5 ecoboost and noticing a misfire on cylinders 1 and 5, I moved coils around. The misfire remained on same cylinders and I had good compression so the plugs were not performing well. I bought these due to colder heat range and closed the gap to .028" and the truck runs amazing. It runs smoother than it ever has !!

Exact Ford OEM replacement plugs for my 2.7 Ecoboost. Perfect manufactured date was less than 3 months prior to installing, giving me the assurance these plugs were not pulled off a dusty shelf. Plugs came pre-gapped at proper 0.028. Exceeded my expectations and performing flawlessly after install and my truck engine running smoothly again.

Great plugs for a tunned Raptor

Perfect fit, step 1 on the path to getting it tuned. Came gapped at 0.28, easy fit. 2024 F-150 Raptor 3.5L

Plugs in box are CYFS 092YPT3 (jAPAN) currently what I am running in my 2.7 10:1 twin turbo. 8 cyl set is M-12405-M50A. I don't feel like chasing plugs through a heat range maze, this # worked for over 106K miles and OE appear hood enough to run another 10-20K. P.M. helps to prevent limping home or towing charges.

2019 Ford Raptor 110,000 miles. Swapped out NGK plugs for these.(no idea of miles on them, looked terrible, was throwing misfires occasionally) 16.5 mpg to 18 mpg same route.

Installed these on my 2017 second generation F150 3.5 Ecoboost with 93 tune. Had issues with spark blowout for YEARS. Tried a ton of different plugs. Tried gapping at .020... These plugs worked. I ohmed the plugs when I got them to determine if these were knockoffs/counterfeit. All plugs tested 4-5k ohms. Thats pretty standard. And knockoffs wont read consistently. I did gap these to .020. Use the proper gapping tool (ten dollars amazon). No issues so far. 22psi boost.

Great plugs, work as they are supposed to.

Made in Japan for Ford. All came in good shape, though loose in the box. A direct replacement for the Ford Fusion Sport with a 0.028" gap set.

I am in utter disbelief on how much of a difference after installing these. I have numerous mods done to my 2018 F-150 limited 3.5 Ecoboost. Was getting some misfire and Inturn sport mode could be a bit choppy and these completely solved that issue. It’s almost like these plugs were the thing needed to bring everything I’ve done to my truck together. If you have a tune BUY THESE! Thank me later

Great product came packaged well with a box inside a box and was 11 days earlier then expected. After opening both boxes and looking over the plugs i got what i expected brand new plugs. Replaced the factory ones that had 152,000 on them and no problems with them. Truck is bone stock and there isn't a misfire anymore as i had one bad plug causing a misfire.

I purchased these 6 spark plugs and the packaging was very very poor one of the spark plugs came cracked. I had to order six more in order to have a complete set of 6. While they are a fantastic product they're packaged extremely poorly and I was going to submit for a refund but it was not worth my time or effort.