Spark Plugs: OEM vs Aftermarket

[Jerrouss]

Hello,

I just want to share my recent experience.
Two weeks ago I started feeling a hesitation or stuttering, right after a fuel fill up on a road trip. Which at the start I thought was bad gas, which ended having a misfire. I didn’t think it was the spark plugs because they were only 1 year old NGK with only 13000km’s on them.
So I went to Mazda this morning and bought 4 new Made in Japan OEM.
The Mazda Partsman also said, due to the SkyActive High Compression engine that it’s best to use the OEM.
So long story short, it’s not worth the savings and stick OEM.

 

[ruthrj]

where did you source the 1 year old NGK plugs? Plenty of counterfeit sources out there, the OEM plugs are likely made by NGK which is why I ask.

 

[Jerrouss]

where did you source the 1 year old NGK plugs? Plenty of counterfeit sources out there, the OEM plugs are likely made by NGK which is why I ask.

They were not counterfeit! They were purchased at Parts Avatar (Canada’s version of RockAuto))

 

[ruthrj]

Any chance you still have the failed plugs handy? Id be extremely interested to see what they looked like (part markings, build quality, tip appearance). Thank you for sharing the heads up. I’ve seen many folks firing the parts cannon without realizing the issue was a failed spark plug.

 

[theblooms]

For what it's worth, I have NGK LTR5BI-13 in my 2012 Mazda5 with the MZR 2.5, and ILKAR7L11 in my 2013 CX-5 with the SkyActiv 2.0. I purchased them from Advance Auto Parts because they routinely have big coupons when you purchase online to pick up in store.

They both have been flawless.

 

[Jerrouss]

Any chance you still have the failed plugs handy? Id be extremely interested to see what they looked like (part markings, build quality, tip appearance). Thank you for sharing the heads up. I’ve seen many folks firing the parts cannon without realizing the issue was a failed spark plug.

Two of the plugs have a reddish to them and the other two are normal.

 

[txt990]

I replaced my 2016 CX-5 sport spark plugs at about 75k with the NGK ILKAR7L11 from advanced auto parts. Was a bit hesitant to use NGK ones instead of Mazda. Now I have about 85k and they have been perfect. No issues with performance.

 

[Rememo]

Two of the plugs have a reddish to them and the other two are normal.

The red on the plugs could be due to two things:

1. An octane booster, or any fuel additive that contains iron.
2. Oxides in the fuel system due to fuel system corrosion.

The second reason would correspond with the decreased performance (misfires) you mentioned.
Perhaps you ended up with one or more tanks of fuel with moisture in it, or if you don't drive very often, the Ethanol in the fuel is absorbing enough moisture to cause issues. It might be worth adding Heet, or other fuel system dryer, to the next couple of tanks of fuel.

Unfortunately, I'm guessing your new plugs will end up with the same red tint until the underlying issue is resolved.

Good luck!

 

[Jerrouss]

The red on the plugs could be due to two things:

1. An octane booster, or any fuel additive that contains iron.
2. Oxides in the fuel system due to fuel system corrosion.

The second reason would correspond with the decreased performance (misfires) you mentioned.
Perhaps you ended up with one or more tanks of fuel with moisture in it, or if you don't drive very often, the Ethanol in the fuel is absorbing enough moisture to cause issues. It might be worth adding Heet, or other fuel system dryer, to the next couple of tanks of fuel.

Unfortunately, I'm guessing your new plugs will end up with the same red tint until the underlying issue is resolved.

Good luck!

You are correct on the octane booster, when I thought it was bad gas, I put a bottle of Gumout Octane booster & a bottle of All in One Gumout fuel injector cleaner. I put 300 km a week just for work a week, And I usually always put Costco Premium or Petro Canada gas in my vehicles. I do think that I had bad gas and I think that was a contributing issue. Now that I’ve filled twice since that potential bad gas, with new Mazda spark plugs, it’s driving EXCELLENT! I am one of those guys that takes care of my vehicles. Even with Castrol Full Synthetic oil, I change my oil every 5000 km and 90% of my driving is highway. At least every two months I put fuel injector cleaner between Lucas or Gumout the other day we were in Montana and I bought the Chevron injector cleaner from all the excellent reviews I read. I’ll try next month.

 

[yrwei52]

The red on the plugs could be due to two things:

1. An octane booster, or any fuel additive that contains iron.
2. Oxides in the fuel system due to fuel system corrosion.

The second reason would correspond with the decreased performance (misfires) you mentioned.
Perhaps you ended up with one or more tanks of fuel with moisture in it, or if you don't drive very often, the Ethanol in the fuel is absorbing enough moisture to cause issues. It might be worth adding Heet, or other fuel system dryer, to the next couple of tanks of fuel.

Unfortunately, I'm guessing your new plugs will end up with the same red tint until the underlying issue is resolved.

Good luck!

If your theory is correct, then all 4 plugs should have red on plugs, not just 2.

 

[yrwei52]

You are correct on the octane booster, when I thought it was bad gas, I put a bottle of Gumout Octane booster & a bottle of All in One Gumout fuel injector cleaner. I put 300 km a week just for work a week, And I usually always put Costco Premium or Petro Canada gas in my vehicles. I do think that I had bad gas and I think that was a contributing issue. Now that I’ve filled twice since that potential bad gas, with new Mazda spark plugs, it’s driving EXCELLENT! I am one of those guys that takes care of my vehicles. Even with Castrol Full Synthetic oil, I change my oil every 5000 km and 90% of my driving is highway. At least every two months I put fuel injector cleaner between Lucas or Gumout the other day we were in Montana and I bought the Chevron injector cleaner from all the excellent reviews I read. I’ll try next month.

I believe you’re over-done on maintenance. But hey nothing wrong with that if you don’t mind to spend money on your CX-5.

 

[LeSheep]

I went to buy spark plugs for the turbo engine. The dealer somehow only got 3 left and they just gave me the NGK number and I thought they are the same thing

 

[Jerrouss]

If I was you, I would wait for the Mazda OEM plugs.