Gen 3 Prius Spark Plugs superceded with hotter plugs

McGeorge Toyota shows the third gen Toyota part number as

90919-01275

Googling that, Amazon availability is spotty, but EBay shows it:

Toyota Lexus Iridium Spark Plug Set of 4 Genuine OEM 90919-01275 SC16HR11 | eBay

A pic from the above:



I'm afraid to ask, but: what about NGK? Just don't go there, lol?

 

Those are what I put back in our 2010 about 3 k miles ago.

Still available and work well.

Nice new avatar BTW.

 

there are many denso iridium tt plugs. Just none listed for prius. why do we have to wait for someone to list the plug?
the heat range is already part of the part number. So, as I see it, the location of the bottom tip of the plug is the only
serious issue we have to be worried about. is there a specification for that number? I am assuming that measurement is
from the rim of the compressible seal ring to the tip. if that is correct, does anyone have any measurements?

 

Hi all.
I am a long time reader but this is my first post here.
I drive 2013 Toyota Auris Touring Sports (1.8L engine) daily (sorry can't post a link yet)

Actually, I am at 70K and was about to order DENSO SC20HR11 plugs (as per manual) to replace them around 80K. Luckily I found this thread and learnt that they were superseded by SC16.
I drive mostly in City (London, UK). Shall I install SC16HR11 (10$ more) or replace with SC20HR11 as they are still available.
Thanks.

 

No
Buy denso ixeh20tt.
They are latest version.
In UK you will be hard pushed to find sc20hr11 now.

I put in new denso ixeh20tt and they are running fine. Slight mpg improvement as well

 

Latest ain't always the greatest.
Which Spark Plugs?! Denso SC20HR11, SC16HR11, or IXEH20TT?? | PriusChat

Was there a wider discussion about this that I missed? Why TT's are best (assuming I am able to get SC20)?

 

Sparkplugs is like engine oil, they are getting better and better. Gen4 Prius use very similar sparkplugs like IXEH20TT as the OEM. It is simply better design that is not available in 2010 when Prius gen3 came out. The heat range changes from the feedback of faulty plugs from high oil consumption in many 2010-2012. Hotter plugs reduce the fouling by reducing the carbon build up on the plugs

 

There's generally a tradeoff, as Denso even explains in their literature; the performance upgrade plug, if the stock plug with its wider electrode is having difficulty igniting your mixture, or otherwise the SC plug made for OE, whose wider (but still iridium) electrode will last longer.

You can look at a number the car's ECM computes for you, called the misfire margin, to find out if there's any reason to think your current plugs are having any difficulty igniting your mixture.

 

Hello all,

So just to clarify, I drive a mixture of highways and local roads in a gen 3 prius - are IXEH20TT the best spark plugs for my car? The rest of the chat has left me somewhat confused. Soz

 

You can do some driving of your normal mixture, and then use a scan tool to pull up your car's misfire margin.

Higher numbers mean the car's ignition is working better. If it's 30 or lower, the car might be at some risk of misfiring. If it's negative, the car is definitely misfiring.

If it's quite high, say near 100 or even above (the number can go above 100), whatever plugs you currently have are doing just fine at igniting your mixture under your normal driving conditions. If the plugs you currently have are the OE ones, designed for longer life, and if they are doing just fine, replacing them with narrower-electrode, shorter-life "performance" ones won't buy you anything (except shorter-life plugs, and bragging rights).

If your current misfire margin is on the low side, then maybe a performance plug could buy you something. (But it might also be a good idea to look for other possible issues that could explain the low margin.)

 

These Denso iridium are all similarly 120k miles rating. They are all not performance plugs, just long life plugs. Newer more optimum design IXEH20TT is effectively can substitute SC16HR11. Similar plugs is used in 2016 Prius and IXEH20TT is actually compatible as OEM for 4th gen

 

glitch