Denso Platinum TT for 2004 Corolla?

[PandaBear]

Originally Posted by Skippy722
All else being equal, iridium has a lower resistance than platinum. Like everyone else said, just get another set or iridium plugs.


I don't think this is how it works, the resistance is nothing compare to other factors (mostly the melting point of the tip, which means the diameter, and the firing voltage). For a conductor what's a few ohms difference when you have a K Ohms in series?

Check the tip size, iridium is likely one size smaller than platinum and way smaller than "copper" steel plug.

 

[kschachn]

The resistance of the tip material is minuscule compared to the overall resistance of the plug.

 

[Gokhan]

Education on the spark-plug resistance:

For the voltages and currents we're dealing with, the resistance of the conductors is a nonissue. Nickel (not copper as many people think) is used as the conductor, which has a high melting point. Platinum and iridium plugs have small pieces of these precious metals welded on nickel.

Now, most spark plugs have a built-in 5000 Ω (5 kΩ) series resistor inside the ceramic between the terminal and center conductor. This is obviously far larger than the resistance of the conductor, which is a small fraction of an ohm. The function of this resistor is to prevent radio-frequency (RF) interference. Without this resistor, your spark plug would act as a microwave transmitting antenna and you would get severe RF interference. In fact, early radio transmitters used sparks to generate the radio waves.

 

[Gokhan]

Regarding Denso Platinum TT, when it first got introduced, I was very excited about it but couldn't find it anywhere. Then, I sent a prepaid envelope with a check to some Advance Auto Parts store in another state and ordered them in this way.

I used them briefly and they performed either the same as the conventional U-groove Denso or perhaps worse. I then took them out and installed the U-groove Denso. They are still sitting barely used. Ever since, I've always use the conventional U-groove Denso.

Think about it: The thinner the spark-plug electrode is, the lower the spark voltage will be (that's why sharp points attract lightning -- they require lower voltage for the spark to form). Therefore, thinner the electrode, lower the voltage, which means smaller the spark, which means less efficient the engine runs. If you want the highest efficiency, you want a conventional plug. Platinum plugs will be less efficient and iridium plugs will be even less efficient.

The reason why platinum and iridium is used is not combustion efficiency but spark-plug longevity.

This said, a twin-tip iridium will be more efficient than a regular iridum because of less fireball quenching. However, they will both be less efficient than a conventional plug, which requires a higher voltage and produces a larger spark.

If your car already calls for iridum, iridium twin-tip is a good idea to increase the efficiency over regular iridum but otherwise it will probably be less efficient than the OEM plug.

 

[HangFire]

I have a 2010 Corolla LE 1.8L. At 105K I changed the spark plugs because I couldn't stand going to the full service interval of 120K. It made no difference in fuel economy (which I track religiously) or anything else. Now at 191K and still no difference. It gets 33MPG in Winter commuting and 35MPG in Summer commuting.

If you want to change your spark plugs, and try a new spark plug, go right ahead. But look elsewhere for slow start and cranking issues.

 

[Skippy722]

Originally Posted by PandaBear
Originally Posted by Skippy722
All else being equal, iridium has a lower resistance than platinum. Like everyone else said, just get another set or iridium plugs.


I don't think this is how it works, the resistance is nothing compare to other factors (mostly the melting point of the tip, which means the diameter, and the firing voltage). For a conductor what's a few ohms difference when you have a K Ohms in series?

Check the tip size, iridium is likely one size smaller than platinum and way smaller than "copper" steel plug.

Originally Posted by kschachn
The resistance of the tip material is minuscule compared to the overall resistance of the plug.


I'm used to dealing with the knuckleheads on the Mopar pages who think platinum or iridium plugs will cause issues lol...

Originally Posted by Gokhan
Education on the spark-plug resistance:

For the voltages and currents we're dealing with, the resistance of the conductors is a nonissue. Nickel (not copper as many people think) is used as the conductor, which has a high melting point. Platinum and iridium plugs have small pieces of these precious metals welded on nickel.

Now, most spark plugs have a built-in 5000 Ω (5 kΩ) series resistor inside the ceramic between the terminal and center conductor. This is obviously far larger than the resistance of the conductor, which is a small fraction of an ohm. The function of this resistor is to prevent radio-frequency (RF) interference. Without this resistor, your spark plug would act as a microwave transmitting antenna and you would get severe RF interference. In fact, early radio transmitters used sparks to generate the radio waves.


Mind if I steal this? Over on the Durango pages people swear up and down that you can't switch from copper to anything else because of various reasons. Even though in ~2014 all the 5.7's went from copper to iridium with no other changes to the ignition system.

 

[zorobabel]

Originally Posted by Gokhan
Regarding Denso Platinum TT, when it first got introduced, I was very excited about it but couldn't find it anywhere. Then, I sent a prepaid envelope with a check to some Advance Auto Parts store in another state and ordered them in this way.

I used them briefly and they performed either the same as the conventional U-groove Denso or perhaps worse. I then took them out and installed the U-groove Denso. They are still sitting barely used. Ever since, I've always use the conventional U-groove Denso.

Think about it: The thinner the spark-plug electrode is, the lower the spark voltage will be (that's why sharp points attract lightning -- they require lower voltage for the spark to form). Therefore, thinner the electrode, lower the voltage, which means smaller the spark, which means less efficient the engine runs. If you want the highest efficiency, you want a conventional plug. Platinum plugs will be less efficient and iridium plugs will be even less efficient.

The reason why platinum and iridium is used is not combustion efficiency but spark-plug longevity.

This said, a twin-tip iridium will be more efficient than a regular iridum because of less fireball quenching. However, they will both be less efficient than a conventional plug, which requires a higher voltage and produces a larger spark.

If your car already calls for iridum, iridium twin-tip is a good idea to increase the efficiency over regular iridum but otherwise it will probably be less efficient than the OEM plug.


You're the first that I came across that claims narrow tip is worse, I'll have to do more research. Some people on maxima.org are very happy with "coppers" every 30k in a car that calls for double platinums every 60k.
The K16TT (Nickel TT) would be right up your alley, too bad it isn't sold in the US.

 

[zorobabel]

Originally Posted by HangFire
I have a 2010 Corolla LE 1.8L. At 105K I changed the spark plugs because I couldn't stand going to the full service interval of 120K. It made no difference in fuel economy (which I track religiously) or anything else. Now at 191K and still no difference. It gets 33MPG in Winter commuting and 35MPG in Summer commuting.

I've never had a spark plug issue myself, or ever noted a difference even on used cars that came with relatively wrong or worn plugs. I might as well clean the original IFR5A11 and put them back in use

Originally Posted by HangFire
If you want to change your spark plugs, and try a new spark plug, go right ahead. But look elsewhere for slow start and cranking issues.

That pretty much sums it up.

 

[GMBoy]

I've been using the Plat TT and Iridium TT plugs a lot lately and I like them. You're really splitting hairs between the 2 because they will both go 100k miles. Iridium is the "better" option but you won't notice any difference using the platinums. Rockauto is where I buy them.

 

[kr_bitog]

Originally Posted by Gokhan
Regarding Denso Platinum TT, when it first got introduced, I was very excited about it but couldn't find it anywhere. Then, I sent a prepaid envelope with a check to some Advance Auto Parts store in another state and ordered them in this way.

I used them briefly and they performed either the same as the conventional U-groove Denso or perhaps worse. I then took them out and installed the U-groove Denso. They are still sitting barely used. Ever since, I've always use the conventional U-groove Denso.

Think about it: The thinner the spark-plug electrode is, the lower the spark voltage will be (that's why sharp points attract lightning -- they require lower voltage for the spark to form). Therefore, thinner the electrode, lower the voltage, which means smaller the spark, which means less efficient the engine runs. If you want the highest efficiency, you want a conventional plug. Platinum plugs will be less efficient and iridium plugs will be even less efficient.

The reason why platinum and iridium is used is not combustion efficiency but spark-plug longevity.

This said, a twin-tip iridium will be more efficient than a regular iridum because of less fireball quenching. However, they will both be less efficient than a conventional plug, which requires a higher voltage and produces a larger spark.

If your car already calls for iridum, iridium twin-tip is a good idea to increase the efficiency over regular iridum but otherwise it will probably be less efficient than the OEM plug.

The twin tip used is not for longetivity only but also for performance. Smaller tip is hotter than big tip so it will burn the petrol mix easier. One more thing is with smaller tip the duration of spark is longer that further enhance the combustion procrss on top of less restriction for flame to spread across combustion chamber.

 

[HangFire]

Originally Posted by Skippy722
I'm used to dealing with the knuckleheads on the Mopar pages who think platinum or iridium plugs will cause issues lol...

Yeah I've run into that. There's some real copper core conventional plug enthusiasts on those forums.

 

[Skippy722]

Originally Posted by HangFire
Originally Posted by Skippy722
I'm used to dealing with the knuckleheads on the Mopar pages who think platinum or iridium plugs will cause issues lol...

Yeah I've run into that. There's some real copper core conventional plug enthusiasts on those forums.


They told me that I would "melt holes in my pistons" if I used platinum plugs on a 2011, and that "the coils will fail very quickly because of the added resistance."

 

[slybunda]

I upgraded the chassis earth cable in my fiesta from the factory 10 or 8awg to 4awg and the difference was night and day. Difference in crank time considerably reduced. Even electric windows moved up and down faster.