2013 - 2016 CX-5 Spark Plug Replacement Guide

1. PE01-18-110: Mentioned in the service manual but superseded by PE5R-18-110
2. PE02-18-110: Mentioned in the service manual but superseded by PE5R-18-110
3. PE5S-18-110: Mentioned in the service manual but superseded by PE5R-18-110
4. (OEM) (PE5R-18-110) NGK 94124/ILKAR7L11 (Laser Iridium): The only available spark plug that you can purchase from most if not all Mazda parts stores/RockAuto.
5. (NON-OEM) NGK 92274/LKAR7AHXS (Ruthenium HX): The newest release; supposedly an improvement over Iridium. It is highly advisable to use OEM plugs unless you would like to be adventurous and explore. Based on my research, it is only recommended to use the same exact spark plug material type or better. In my case, I am using Ruthenium as a substitute because I am curious to see if there are any benefits. See link/attachments for more details (Ruthenium Spark Plugs).

1. (4) Spark Plugs of your choice
2. Paper Towels: To clean of all of the debris on top of the engine bay so that it doesn't get inside your ignition system.
3. 3/8 Drive Breaker Bar
4. 3/8 Drive Ratchet
5. 3/8 Drive Torque Wrench
6. 8 mm socket: Used to remove the (4) bolts holding the ignition coil.
7. 10 mm socket: Used to disconnect the negative battery terminal to avoid causing a short.
8. https://www.amazon.com/dp/ (commissions earned)or 14 mm socket: Used to remove the (4) spark plugs. I have both the Harbor Freight 5/8 inch and 13/16 inch spark plug sockets and both do not fit. I have also tested the 9/16 inch socket and it fits perfectly in addition to having a very useful magnet inside so I highly recommend the one that I've linked. You could potentially get away with using just a regular 9/16 or 14 mm deep socket but there's no rubber gasket inside that would cushion the spark plug porcelain so you run into the risk of damaging it if you're not careful. Most of the 14 mm spark plug sockets that I found are 12-point and I prefer 6-point sockets so I opted for the 9/16 6-point socket instead.
9. (Optional) Spark Plug Gauge/Gap Adjuster: Mazda recommends the use of "wire type plug gap gauges" but you could also use blade types as well if needed. The reason why you would need a gap gauge is to measure the spark plugs gap (distance between ground electrode and center electrode) to confirm that the factory set values are within the OEM tolerance. If the spark plugs are not within the tolerance, then it would alter the amount of voltage draw required to cause the spark and this may result in misfires, fouling, loss of power, poor fuel economy etc.
10. (Optional) Multimeter: You can use this to measure the resistance of your old/new spark plug and according to Mazda, your PE5R-18-110 should be within 3.0 - 7.5 kOhms (kΩ). For my Ruthenium plugs, I was unable to get a reading at all and I've attempted multiple times (ground electrode and terminal nut were my contact points) but the only thing I can think of is that I am not performing this procedure correctly.
11. (Recommended) Dielectric Grease: The purpose of the dielectric grease is to aid in the: (1) installation/removal of the spark plug, (2) inhibiting moisture and (3) preventing an arc from occurring. It is recommended to use a thin coating of dielectric grease between the (1) porcelain portion of the spark plug or the insides of the (2) coil-on-plug-boot design of the SkyActiv 2.5l.

• Based on the recommendation from NGK, you DO NOT need anti-seize as the anti-seize will alter the torque specifications of the spark plug and you run the risk of damaging the spark plug/threads from over-torqueing. (NGK Spark Plugs)

1. Anti-seize

NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize.

Anti-seize can act as a lubricant, altering torque values up to 20 percent, increasing the risk of spark plug thread breakage and/or metal shell stretch. Thread breakage can sometimes involve removing the cylinder head for repair. Metal shell stretch changes the heat rating of the spark plug and can result in serious engine damage caused by pre-ignition. Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental.
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• NGK advises only to adjust the gap of the spark plug +/- 0.008 inches (0.2032 mm)
• Highly advise anyone doing this to use a 3/8 breaker bar, ratchet and then hand loosen the spark plug all the way using the socket extension.
• The connector on the coil on plug boot is very easy to disconnect. Just simply press down on the latch and slowly wiggle it left/right and pull backwards to disconnect.

1. Disconnect negative battery terminal (negative (-) symbol/black color) using 10 mm socket.
2. Remove the engine cover by pulling upwards so the (4) grommets will release.
3. Clean off any debris
4. Remove (4) 8 mm bolts holding the ignition coils in place
5. Gently pry the ignition coils upwards in a back and forth rocking motion and put the ignition coils aside in chronological order as they were removed.
6. Use a 3/8 mm breaker bar with the 9/16 (14 mm) socket to break loose the (4) spark plugs.
7. Use a 3/8 mm ratchet to remove the (4) spark plugs.
8. Install the new spark plugs and torque the spark plugs to spec (see D).
9. Lubricate the inside of the coil on plug boot/spark plug porcelain with dielectric grease
10. Install the ignition coils back and install the bolts back torque to spec (See D).
11. Before putting the engine cover back on, connect the negative battery terminal back on and turn the car on to see if there's any issues.

Pictures Below: