10,000 miles on Denso iridium tt spark plugs

[Kool1]

I've used the factory Denso iridium and NGK iridium spark plugs in my 03 Honda CRV and have always noticed that the idle would not be really steady after 7,000-10,000 miles; in addition, power requirements always requires me to dig a little deeper into the gas pedal around the same mileage (I am very sensitive to slight changes in power and idle rpms). With Bosch iridium I was getting gas fouling after about 10,000 miles to the point it would occasionally pop with a misfire on hard acceleration. By the way, my air filter is clean.

The Denso iridium tt spark plugs have been consistent from day one. The idle is rock solid, acceleration feels the same as the day I installed them and my mileage is great. Denso claims that I should get 100,000 plus miles out of these spark plugs. I wonder if this will occur?

 

[SuperDave456]

You can do 120k miles on Factory Iridium easy.
If Bosch isn't OEM that's why they act up.

 

[HerrStig]

Bosch may have made the first commercial spark plugs, but I quit using them in the early 70s. Every one of my SAABS came with NGKs OEM. I found the best plug for my BMW motorbike to be an NGK one heat range COLDER than the Bosch.

 

[Sequoiasoon]

One thing to remember also is that the TT has either an iridium or platinum tip ground also. Many of the regular iridiums just have the center electrode as iridium. I went 30k on a set in my Corolla way back. Spark plug gap tripled as the ground wore away.

 

[Vuflanovsky]

I've never had any issues when I stuck to the OEM plug. If it came with NGK or Denso then the exact replacement is what went in it.

While I think you definitely can get 100K out of a set of iridium plugs, you'll probably notice a reduction in performance by the 60 or 70K mile mark. I've typically put in new plugs at about this mileage for my last two cars ( both Japanese using NGK ). IMO, the $50 for a set of 4 plugs is worth it versus getting every last mile and relatively poorer performance out of them for the back side of their usable life.

 

[slacktide_bitog]

Really? Only 7000 miles? That's less than one OCI! If iridium plugs are fouling before 10k, there's something wrong with the car, not the plugs.

Even cheap copper plugs should last 30k.

Is your car leaking oil? Leaks around the valve cover gasket and/or spark plug tube seals could cause fouling when oil gets all over the plug. When you change them out, are the wells filled with oil?

The factory iridiums should last at least 100k.

How many miles have you put on your Denso Iridium TT's?

 

[Olas]

Use copper plugs, check & clean & tighten all earths, use bigger coils if available then report back.

Do you have a scanner?

 

[SHOZ]

The Denso and NGK TT iridums are copper plugs. They should last 100k, 80k easily. Make sure the gap is right for the motor and this may not be what the manufactures specs or what they plug is pregapped at.

Last summer we changed the OEM AC plugs on my son's Chevy Malibu at 120k. They looked nearly as good as the new ones.

 

[Jetronic]

try gapping these...

I love those plugs