Spark plug change

Plugs don't look too bad

do you have plan for the rear sway bar too? Big improvement with both tower brace and rear sway bar

 

How are you going to get that carbon out of there?

 

There is an association with carbon and oil consumption due to the ports on the oil control rings being blocked.
I advise that you use only Tier 1 gasoline. One guy on this forum used Techron fuel system cleaner 4 tanks in a row and reduced his oil consumption.

 

I thought the revised plugs were "hotter", ie more able to burn off deposits?

 

"The level of heat range is connected to low or high speed driving. The initial choice for the right heat range is a result of expectations towards average use of the engine. After a few years of experience with this engine, the manufacturer decided to lower the heat range."

Above is an excerpt from your link. Man they word it awkwardly, the bold text.

In the following link:


How Do I Find a Colder or Hotter Plug?


they spell it out: with Denso plugs a lower number is a hotter plug, ie: one that gets hot quicker.


How Do I Find a Colder or Hotter Plug?


Excerpt from the above:


"Denso Iridium Power plugs feature the Heat Range at the end of the part number. For example, IK20 has a Heat Range of 20. Denso plugs get colder the higher the number, hotter the lower the number. Starting with part # IK20 (Heat Range 20), a colder plug would be # IK22, a hotter plug would be # IK16."

I guess Denso and Toyota work closely, and they're finding too much deposits building up on the stock plug, and they've more-or-less replaced the "20" plug with "16" (slightly hotter). Further, if you go looking for the 20 plug, you'll be told it's not available, replaced by 16.

 

Maybe just Denso; NGK might be the opposite, lol.

 

looks like the 20 was good for hwy driving and this is how they tested the car, but in the real world too many people are city driving and they had to adjust for that?

 

Also, from the article you posted, seems like the stock plug was almost purpose-built for the Prius. So when it proved to be too cold, they just discontinue it, superscede the 20 with 16. This maybe avoids Toyota needing to inform dealerships or owners: when you go looking for the 20 you're redirected to the 16.

 

So what is the new Denso part numbers for the new TT plugs? I am still seeing only 20's and no 16's from online seller. Thanks!

 

Is anyone concerned that the hotter 16 plugs when used under high-load, high-throttle conditions could be more likely to create pre-ignition or even detonation, particularly if the ICE has carbon accumulations in the combustion chamber and thus a slightly higher than originally designed compression ratio?
Based on very old experiences with 2-stroke and 4-stroke engines, Mr Worst Case Scenario here worries about melting through the tops of the pistons. I rather wish they would continue to produce both heat ranges and let us decide what to install.