Spark Plug - SP539X

These Motorcraft SP-539X spark plugs are the real deal: genuine OEM Ford parts, not cheap knock-offs or counterfeits that flood the market. I was careful to buy from a reputable seller to ensure authenticity, and they arrived in proper Motorcraft packaging with all the correct markings.As a former Ford technician with 15+ years in the automotive industry. Installation on my 2015 Ford Fusion with the 1.5L EcoBoost engine was straightforward and easy—it took me less than an hour with basic tools. As with the majority of OEM Motorcraft plugs, these come pre-gapped. I checked anyway, and they were dead on at 0.028”. Ford’s factory specification for this engine is 0.025”–0.030” (0.65–0.76 mm). There were no issues fitting them perfectly, as expected from factory-spec parts.Since installing them, the car runs smoother than ever: idle is steady, acceleration feels crisp, and no more occasional misfires I was noticing before. I’ve also seen a small but noticeable increase in fuel economy.Repair Notes:If you have access to compressed air, I highly recommend using a blow gun or air nozzle to remove any dirt and debris from the cylinder head after removing the coil packs but before removing the spark plugs. This will greatly reduce the chances of foreign contaminants entering the cylinders.I also recommend disconnecting the wiring harnesses from the four fuel injectors before removal. This provides extra clearance, allowing your socket and extension to align straight and parallel with the spark plug well, which reduces the risk of cross-threading or cracking the porcelain on the spark plug during installation.The torque specification for these plugs is 9 ft-lbs (106 in-lbs or 12 Nm)—use a torque wrench for accuracy and avoid over-tightening. Additionally, it is recommended to apply a very small amount of anti-seize compound to the threads (but never on the electrode end) to prevent seizing in the aluminum head over time.If you’re maintaining a 1.5L Fusion or Escape, stick with these genuine Motorcraft plugs for peace of mind and performance. Worth every penny! 5 stars.

Works as it should

Good product, works as intended. Amazon needs to improve their boxing, spark plugs where flying around in the box

They are sparkplugs. What do you want me to say?

Genuine Motorcraft.

It caused a short on my car

Fits my Ecoboost 1.5L. Engine is smoother and quieter afterwards.

Quality spark plugs at a very good price.

I would not recommend these spark plugs. Two of the four failed after only a couple of minutes of engine operation. One ceramic insulator shattered, and another cracked. This caused engine misfires immediately after installation. Very disappointed with the quality.