I know that the company line here is to use NGK plugs (and definitely not Bosch). I am wondering if anyone has any extended experience with Denso double platinum plugs as to whether they are harmful to the engine life or whether, as advertised, they last longer and have fewer misfires.
ThanksKen K
Q45: Denso double platinum spark plugs
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Q45tech
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The NGK plug was designed for the engine [exact combustion space].Even 0.001" length difference can make a difference.
Just like the Denso which were the oem for Toyota/lexus in which we would never use NGK for substitution.
Believe me if we could stock one plug instead of 6 for the cars we service we would.
When you get >200k on engine you must reevaluate if 60k is often enough vs say 100k when the engine is brand new.Experience says that 60-100k, then 60-80k, then every 50k till destruction..........depending on valve stem seals/rings.
Just like the Denso which were the oem for Toyota/lexus in which we would never use NGK for substitution.
Believe me if we could stock one plug instead of 6 for the cars we service we would.
When you get >200k on engine you must reevaluate if 60k is often enough vs say 100k when the engine is brand new.Experience says that 60-100k, then 60-80k, then every 50k till destruction..........depending on valve stem seals/rings.
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maxnix
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If I may step-in here, I think the point is, if you want to experiment, fine. But why risk a $15K engine for the non-OEM sparkplug which works flawlessly, for any other reason?kdkrone wrote:Have you seen any specific damage from the use of Denso plugs? If not, what would you anticipate? - Thanks Ken K
Bosch +4 are known VH45DE killers, but owners still buy them and the advertising hype.
Please read Q45tech's post again. T-3 does what they do based on years of experience across a large sample of Infinitis (especially G50) and Lexi.__________________Brian1995 Q45 & Q45t & 2000 Q45
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Maxnix,
Thanks for our response
The main reason for concern is that my mechanic strongly recommended the Denso plugs and installed them while he was checking out a problem of missing (which turned out to be a bad injector) and the question now is whether to have the plugs changed back to the NGK.
If the issue is a hundred plus dollars to replace the Denso plugs because of potential harm to the engine, that is a no-brainer and if it was the Bosch plugs that he had used, then I would definitely change them out. Basically, when my mechanic suggested the plugs, I agreed (albeit an uninformed decision on my part and I acquiesed to a hopefully more knowledgeable person), so I certainly cannot expect him to replace the plugs for nothing. But the question is not whether the Denso are better than the NGK but, rather, will they will be harmful. So I was seeking some input as to whether anyone had any experience with the Denso plugs.
Thanks,Ken K
Thanks for our response
The main reason for concern is that my mechanic strongly recommended the Denso plugs and installed them while he was checking out a problem of missing (which turned out to be a bad injector) and the question now is whether to have the plugs changed back to the NGK.
If the issue is a hundred plus dollars to replace the Denso plugs because of potential harm to the engine, that is a no-brainer and if it was the Bosch plugs that he had used, then I would definitely change them out. Basically, when my mechanic suggested the plugs, I agreed (albeit an uninformed decision on my part and I acquiesed to a hopefully more knowledgeable person), so I certainly cannot expect him to replace the plugs for nothing. But the question is not whether the Denso are better than the NGK but, rather, will they will be harmful. So I was seeking some input as to whether anyone had any experience with the Denso plugs.
Thanks,Ken K
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maxnix
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It's a roll of the dice. Ask your mechanic (who is not an Infiniti service technician) if he will guarantee absolutely that the Denso will not cause problems. If he says yes, get it signed in writing. If he says no, then have him change them back to OEM NGK at his expense. It would be good to let him know you know what the specified sparkplug is. Maybe the Denso insulators are designed to conduct heat a little differently for a Lexus head? What if the reach is just a little longer and allows the VH45DE piston to stike it at high rpm as the rods stretch when they are hot?
My guess is you should be safe, but why should you have to assume the burden of risk for your mechanic's overriding the OEM specifications?
It's your $15K engine on which he is experimenting!__________________Brian1995 Q45 & Q45t & 2000 Q45
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My guess is you should be safe, but why should you have to assume the burden of risk for your mechanic's overriding the OEM specifications?
It's your $15K engine on which he is experimenting!__________________Brian1995 Q45 & Q45t & 2000 Q45
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kdkrone:
Your most recent post shows the situation is different.The denso's do not have a rep as harmful, as a matter of fact we have an experienced Infinti tech on this board who thinks of them as highly as the NGK's.If I were about to buy plugs I'd still prefer the NGK's but not to thepoint of ripping out brand new Denso's.
I <would> rip out brand new Bosch's or Champions.
Fred..
Your most recent post shows the situation is different.The denso's do not have a rep as harmful, as a matter of fact we have an experienced Infinti tech on this board who thinks of them as highly as the NGK's.If I were about to buy plugs I'd still prefer the NGK's but not to thepoint of ripping out brand new Denso's.
I <would> rip out brand new Bosch's or Champions.
Fred..
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Q45tech
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Independents have a hard time with substitute [non oem] parts as they almost always bite them in the arse. They experiment because they need the price margin and at best the dealers give them a 25% discount [usually 15% unless they buy a lot frequently].
Imagine a business climate where the dealer gets to double their parts cost and you can only mark things up 15% [same parts cost to owner]. Then you have to charge less labor to sound competitive.
I can buy Metal Master Q pads for $35 vs oem Q pads for $61.....the retail price of pads is $80..........Am I foolish enough to think MM pads will work for the average owner ...........No! The groaning noise will yield a compliant.
We use $17,000 per week in parts/fluids/supplies, saving another 10% would be significant, even 5%, but not worth the risk.
Just because a pad fits is no reason to use it! Same with spark plugs, and many other maintenance items.
Imagine a business climate where the dealer gets to double their parts cost and you can only mark things up 15% [same parts cost to owner]. Then you have to charge less labor to sound competitive.
I can buy Metal Master Q pads for $35 vs oem Q pads for $61.....the retail price of pads is $80..........Am I foolish enough to think MM pads will work for the average owner ...........No! The groaning noise will yield a compliant.
We use $17,000 per week in parts/fluids/supplies, saving another 10% would be significant, even 5%, but not worth the risk.
Just because a pad fits is no reason to use it! Same with spark plugs, and many other maintenance items.
Just to clarify this discussion again for everyone:
The question is not, if he should subisitute Denso's over NGK's, but if its neccessary the expense to take out new Denso's after they are already in.
And unlike the Champion or Bosch plugs, the Denso's dont meet the criteria for taking them out once already in.
Fred...
The question is not, if he should subisitute Denso's over NGK's, but if its neccessary the expense to take out new Denso's after they are already in.
And unlike the Champion or Bosch plugs, the Denso's dont meet the criteria for taking them out once already in.
Fred...
We all do many non OEM things.
I had a multi year factory certified infinti technician send me a lenghty email on how well the Denso's do in the Q.Yes teh Denos are likely the only non OEM that are ok in the Q.
It is <not> worth $500 to take them out just to go OEM.That money would be spent with better effect on other mainteance items
As much of a perfectionist as I am myself (as is well known to this board) and prefer NGK, I would <not> take out new Densos.
Thats just plain common sense with known good plugs, that just happen to not be OEM.
And even Dennis' post that not imply that and is simply a general statement how as a rule of thumb one should go with OEM.
Fred..(sigh)
I had a multi year factory certified infinti technician send me a lenghty email on how well the Denso's do in the Q.Yes teh Denos are likely the only non OEM that are ok in the Q.
It is <not> worth $500 to take them out just to go OEM.That money would be spent with better effect on other mainteance items
As much of a perfectionist as I am myself (as is well known to this board) and prefer NGK, I would <not> take out new Densos.
Thats just plain common sense with known good plugs, that just happen to not be OEM.
And even Dennis' post that not imply that and is simply a general statement how as a rule of thumb one should go with OEM.
Fred..(sigh)
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maxnix
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Where's the money?
But not with things affecting moving parts in the engine (except for some crazy Australians:D). Quite frankly, the only none OEM thing I will do is Tokico blues, the heavier Stillen rotors and add a transmission cooler. All at my risk. (Thank you board!)PalmerWMD wrote:We all do many non OEM things.
And even Dennis' post that not imply that and is simply a general statement how as a rule of thumb one should go with OEM.
Fred..(sigh)
The point is who guarantees the recommendation, the part and the workmanship? In Ken's case, Ken does by assuming all the financial risk if something does go bad. This may not be acceptable to Ken.
I agree the Denso should work, but I won't guarantee it. Neither would T-3. Nor would they install an NGK in place of a Denso in a Lexus.__________________Brian1995 Q45 & Q45t & 2000 Q45
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