Best spark plug (1 Viewer)

[hotdiggitydamn]

This thread is almost as good as Tiger King. Good info ya’ll!

 

[Lonegrasshopper]

Here is my analysis of it. Kind of an exercise for my brain (this is what I do for work)

1. Suppliers: contracts/purchasing/redundancy/manufacturing capacity.
2. Performance: reliability/longevity/performance/mileage/serviceability.

Toyota builds and sells everything on a JIT model (just in time). They know that their demand can be massive, but also needs to be fluid. The easiest way to make sure they always have the plugs they need without having to cash flow them far in advance, is to find manufacturers with the right capacity, award both contracts and require them to work in parallel. I'm insulated from risk if one firm's production line goes down. I get to dictate the price as parallel contracts means I can shift to the other if one pushes back on something.

Another dynamic:

Toyota builds their entire production line around a couple of motors, and they stick with that motor for at least 5 years - usually more than 10 years. If you have relatively matched firms like Denso and NGK supplying (for example) ALL the plugs for the 1GR-FE motors that Toyota builds for a decade, that brand is simply going to dominate the other company.

Toyota doesn't want that. They want both firms constantly under the gun because their competitor is neck and neck with them on capacity, technology, quality, pricing, and availability. Toyota then has leverage over both Denso and NGK for at least the spark plugs.

If I'm Toyota and really want to prove a point, I could go as far as to put both brands' spark plugs in a motor design at the same time. It certainly proves their products can be used interchangeably and I don't care who sells which plug to me as long as I get it on time, the quality is great, and they don't ever think about changing their price.

Another dynamic:

They did it to see which product has the best longevity, reliability, and performance. With a few hundred thousand motors sold a year and how long Toyota plans to run it...sure, it makes sense to do this. But then they ran mixed plugs in the 1GR-FE for almost a decade. They had results back on the plug performance within 5 years. I think this was a business driven decision with performance/product quality data benefits.


Back to OP's question, I've run both in several 4.7's and both the NGK and Denso plugs are great.

I love your analysis, and I agree. Both plugs are great.

 

[Hokie99]

What's the best spark plug for the LX? 2002 model.

DENSO: SK20R11
or
NGK: IFR6A11

I have always found that the Densos work the best. I would also replace the coil on plug boots at the same time with Denso boots. About 40 bucks. By replacing the boots you can save your coils a lot of wear and tear over time.

 

[FxFormat]

I just did mine today, they had the SK20R11 in there, done by Lexus 75K miles ago. I saw one evidence of a new coil replaced, #8 with OEM denso, the rest are original and none of the coils looked brown. The plugs themselves don't look too bad, all were very loose however, there were anti seize present. I took them out and installed IK20TT ones with no anti seize. I did 20ft lbs

New ones felt a little smoother and idled smoother, could just be placebo. I'll change those again in 60K

Check out the valve cover, a little dusty but not a drop of oil is seeping out, 200K miles now. Wish my german cars were built like this, my benz is already leaking at the valve cover at 50K miles.

 

[2020 Rocks]

I've always used NGK in toyotas, never had a problem.

 

[NoTempoLimit]

...Wish my german cars were built like this, my benz is already leaking at the valve cover at 50K miles.

Don't get me started on the Deutsche Technik... Formerly owned and wrenched on 3 BMW's (details in Sig). Love the way those cars drive and the superior ergonomics. And the SOUND of the straight-6 (sounds like V-12 at low rpm).

But damned if they don't make some dumb-ass choices of materials in critical areas (like plastic in the cooling system UNDER the intake manifold) ruining a a good engine design.

50k miles is average for valve cover gaskets on any German engine. And they're only going to get worse since they aren't going to put any more engineering effort on the I.C. engines. We've probably already seen the best German car engines ever to be made.

I won't even discuss transmissions except to say that I will never again buy a German car that does not have 3 pedals. Since BMW no longer makes those, they've lost me.

From what mechanics have told me, the high line Mercedes are the best of the German cars in terms of durability. From your pic it seems you have an S class roadster so you already have the best.

Can you comment on the DENSO TT plugs now that you've had them in for a while?

 

[2001LC]

The plugs themselves don't look too bad, all were very loose however, there were anti seize present. I took them out and installed IK20TT ones with no anti seize. I did 20ft lbs

Hope you don't mind, this is your picture. I'm not seeing signs of anti-seize on your old plugs.
I pulled your picture from above. So I could zoom in. The threads don't have built up within the grooves.

I find threads full of crud, of anti-seize used. Coloration varies with how much combustion gases, passed the thread. This one below, had some combustion leakage. It walked out about 1/4 turn then froze. Some other in same engine, were more golden. Those plugs hadn't loosened, or not much. Others more blackened, they had walk out the most. All 8 plugs' thread where filled. This was first time I'd added anti-seize, which I'll never do again.

BTW: It looks like I added a lot of anti-seize. That is not the case. I wipe lightly after applying the Anti-seize, out of fear I'd get copper in the engine cylinders/rings.

 

[lehiguy]

I developed a serious misfire earlier this year. I pulled out all eight Denso plugs, one was nearly in two pieces, three more were defective with the top half rotating independently of the bottom. I put in NGKs.

 

[2001LC]

Many sellers of bootlegs spark plugs in the market, mostly on ebay. Likely thats is what you had. It's one of reasons I've gone to the Denso Twin Tip 0.4mm. Even those are being counterfeited. But I can spot the their thicker electroid right off.

 

[Nightbrew]

Is it recommended to put dialectic grease on the plug/coil?

 

[2001LC]

Denso boot kits have a small pack of dialectic. They instruct to add a small amount in boot.

 

[AlpineAccess]

Dielectric on plug ceramic but I don't put it on the node or spring. Do not put on threads.

 

[Nightbrew]

Dielectric on plug ceramic but I don't put it on the node or spring. Do not put on threads.

Why put it on the ceramic?

 

[AlpineAccess]

Why put it on the ceramic?

The only reason I use dielectric is to prevent plug boots from sticking to the ceramic. I haven't had an issue with the contact points not releasing but plenty of struggles getting a boot off.

 

[2001LC]

Good call @AlpineAccess. I put a dab in tip of new boots, after assembly on the coil. I then take my needle nose and insert about 1/2" in tip of boot and spin to distribute D-grease. The amount of D-grease Denso gives in the kit, is very small. Even so, I don't even use it all, on 8 boots.

Edited 9-29-20
I don't bother greasing used boots. But perhaps I should.

Why Denso recommends adding to boot, I'm not sure. But I did not think, it to keep boot from sticking on the plug. In fact I find the coils harder to pull off once boot greased. I assumed the purpose was for great or tighter fitment to eliminate flasher over. That is why we reboot and why plugs have "Corrugated ribs" is to prevent flashover.

 

[sacman]

I highly recommend NGK. I used them without any issues on VW, Toyota, Lexus, BMW and Porsche

 

[Nightbrew]

The only reason I use dielectric is to prevent plug boots from sticking to the ceramic. I haven't had an issue with the contact points not releasing but plenty of struggles getting a boot off.

Ok, that makes sense. I have never used dg on any non electrical application. I always enjoy a good multi tasker.

 

[AlpineAccess]

Ok, that makes sense. I have never used dg on any non electrical application. I always enjoy a good multi tasker.

I read what I posted before and can see how there is some confusion - just to clarify: I just put the dielectric directly on the spark plug, and not on the inside of the boot (both work the same way). The dielectric is still being used in an electrical application this way as it needs to be compatible with the terminal end which it will invariably get onto when switching plugs.

I've only ever heard of dielectric being used on electrical connections, and their rubber boots, o-rings, seals, etc. as its cross compatible and a long lasting lubricant. But I am sure it could be used on anything that is not silicone based to prevent water intrusion and corrosion.

 

[Bisho]

Interesting fact, on some Toyota motors, My 2007 FJ for instance, come from the factory with both. One side has Denso and the other NGK. Now I do not know about Cruisers since I picked up my 2006 LX470 used. Why did they do this?

The left cylinder head and right cylinder head are built in different factories, just like the left Twix and right Twix factories.

 

[NoTempoLimit]

I have read that Toyota takes JIT (Just In Time) supply to such an extent that their factories only have 1 production hour worth of parts on hand at any time. The cylinder heads would come from opposite sides of the engine assembly line, each of which may have been supplied by a different supplier.

Not as romantic as "one man builds one engine" like Ferrari, or how BMW used to hand-build the engines for the M series cars. But you can't argue with results.

Also, as we know, the 2UZ-FE is also built in Alabama for the pick-ups. Anyone know what spark plugs they are being fitted with?

Still nobody besides 2001 LC can give review on the DENSO IK20TT plugs?