Platinum plugs necessary?


Just in case you missed this, OP, this is important and will save you money. You don’t need to take it to the dealership if you don’t want to. It will not void your warranty if you have the work done at an independent shop. Dealerships are almost always more expensive, and there is no guarantee that the mechanics at the dealership will be any better than the mechanics at Joe’s Independent Garage.


Standard Copper plugs last about 30-40 thousand miles. Platinum can last from 60k to 80k. And Iridium plugs last 100k miles.

I couldn’t find a Platinum plug for this vehicle…only Iridium. I’d be surprised if it’s not spelled out in the owners manual what the plug type is.


LOL, I think you caught an error by the Hyundai tech writer.


Not to beat a dead horse, but one motivation an owner might decide to change the plugs more often than the manufacturer suggests is b/c they can become stuck over time and difficult to remove without damaging something else in the process. The manufacturers want to make the car appear inexpensive to maintain for those buyer who pay attention to the “long term cost to own” column in the ratings, so there is a monetary motivation for the manufactures to spec long spark plug change intervals.

Whether this applies to a particular make/model/year depends a lot on how time consuming it is to change the spark plugs, and how much the spark plugs cost. For a car like my Corolla using $2-$3 ea spark plugs and 45 minutes to change, it makes a lot of sense to error on the side of changing them too frequently. For a sideways mounted v6 where the intake manifold has to be removed to change the spark plugs, and which use expensive plugs, it might make more sense in terms of total long term dollar cost to change them on the manufacturer’s schedule and knock on wood you don’t get the stuck-in-the-cylinder head problem.


It’s an alloy. Pure iridium is too brittle and a poor conductor. Adding Rhodium improves oxidation wear and conductivity. I mentioned once before on here about experimenting with harvested electrodes from Iridium spark plugs. We had SEM analysis done but even under magnification you can tell it’s a sintered electrode…


A sincere thanks for the clarification. I try to learn something new most every day. You’ve helped me fulfill that goal today.


Thank you everyone,

I found a great guide here:

I would have preferred to replace them with Champion plugs that have a solid Iridium core, but all I could get were the OEM Denso plugs that have a copper core and are actually twice the price, but I didn’t care much about that.

The most difficult part of this turned out to be disconnecting the plug wires from the boots which endedup taking hours. Apparently after pulling the little, grey slide lock back you have to awkwardly press down on the tiny black piece in the middle while trying to pull the plug off which turned to take a tremendous feat of strength and dexterity to pinch down with finger tips as hard possible and pull back without breaking anything.

After a few hours of pinching, pulling, take a break and come back I finally heard the satisfying click from each plug and almost brought tears to my eyes when the last one came off.

The man who made the guide above shows the condition of the plugs at 45k and mine is at 58k and plugs all look a lot more crispy around the ceramic and electrode tips than his did, so these little turbo engines must be a lot harder on these than non-turbos as some has suggested.

On a side note I had a p0420 code show up a couple weeks ago also that I cleared and hasn’t returned, but I’m hoping this new set of plugs will put that to rest also.

Before tons of people start posting here about catalytic convertors and O2 sensors I know about those and how to check them and will be keeping an eye on things :-).


Sounds like you have things under control there OP, good job. Next time you visit an auto parts store, ask if they have a special tool they sell to help with removing those spark plug boots.


Trust me…stick with the manufacturer recommended plugs. I suspect Denso or NGK are the recommended plugs for this vehicle.

Are you sure the Champion plugs are Iridium core? I know NGK isn’t. They are Copper core, but with Iridium tip. Same with Denso.

If you’re looking for pure performance, then stick with Copper core plugs.


For the record, my experience with Champion plugs in automobiles has been terrible. In my opinion they’re cheap junk, nothing more.


@the_same_mountainbik. I grew up in the days when a Champion J-8 spark plug would fit almost anything. We used them in our 1952 Dodge flathead 6, our 1954 Buick OHV V-8, our Lawnboy two stroke mower, our rototiller with a four stroke Lauson engine and our Evinrude twin cylinder 3 horsepower boat mower. I used to think that any engine that wouldn’t run on Champion J-8 sparkplugs wasn’t worth having.
Today, I follow the manufacturers’ recommendations for spark plugs for my vehicles, but my mowers and rototiller run just fine with Champion spark plugs.


Without challenging your opinion, there are Champion double platinum plugs in one of my cars that seem to be without substitute (IOW, other brands and plugs will not work as well in this particular car’s model and generation).
And it’s not just my experience; it includes the experience of others on a forum specific to the car.

None of this means I would automatically use Champion plugs in my other cars.


I just pulled the Iridium plugs from my 2014 Mazda 6 this weekend with almost 98,000 miles on them. They came out easily and had some normal soot but the electrodes were clean. I measured the gap and they were still at the factory set gap of .044 inches. I still dropped in a brand new set of NGK Iridium plugs that were listed as OEM by Mazda. The dealer wanted $30 a plug but I got them for $11 each online (same model and stock number). I compared the old plugs to the new ones as I put them in. Except for that little bit of soot on the old, they looked the same. I’m glad I changed them but I think the old ones could have safely taken me to 150,000 miles without trouble. NGK and Denso Iridium plugs last a really long time.


IMHO it’s good to replace them even if they look good. These plugs seat on a square shoulder with a hollow metal washer designed to deform under the specified torque to provide and absolute seal. Once deformed, the sealing washers are not designed to be reused. I know of many who reuse the old plugs apparently without incident, but I prefer to use them as they were designed to be used.


My Chryslers’ OE plugs are Champions. My GM cars use AC Delco. I always use the manufacturer specified plugs in my vehicles.

For the record, my experience with Champion (or any OE plugs) has been outstanding. In decades and hundreds of thousands of miles they have never disappointed.


Fair enough, and I agree with the philosophy of always using the manufacturer specified plugs.
I’ve driven only riceburners since my first Toyota in 1976, with the exception of one vehicle (a Saturn), and I wouldn’t recommend them for riceburners. I use a Champion in my snowblower, but I change it every fall anyway, and simpler engines seem to be less fussy about their sparkplugs.