2024 Taco User Manual and Warranty Maintenance Guide

See attached

 

dang 40k spark plugs interval
at least it's a lot less work than doing that on V6, perks of inline 4

 

Yeah all look on top...not even sure I would finish a beer changing them out.

 

I'm thinking because of the higher combustion chamber temps maybe?

 

My speculation:
assuming we're all using the same high-end iridium plugs
port injection naturally aspirated engine, such as found on 2nd gen 1GR-FE, can go as high as 120k miles
3rd gen 2GR-FKS, it's shortened to 60k, the difference there is that it has direct injection
now with both direct injection and turbo charging, we see 40k mile interval, same as the turbo v6 Tundra

So my guess is the plugs live a much tougher life in the combustion chamber due to direct injection (unburned fuel turned into carbon deposit) and turbo charging, I would assume higher combustion temp but if really depends on how they tune the engine

 

The second gen 4.0 plug change interval is 30K. The 4Runner 4.0 is 100K.

 

^Dual-VVTi 1GR is specified with iridium plugs from the factory. I changed mine a few months ago.

 

It's actually an EPA requirement. They are forcing automakers to change plugs at earlier intervals to make sure there are no misfiring vehicles polluting the environment.

 

You have a source for this info? Very interesting.

 

Manufacturers don't want to cut corners when it comes to secondary ignition components. Spark related misfires are a major cause of catalytic converter failure. They have to warranty the converters until 8/80 so they don't want to take any chances

 

They've been out for more than a month: https://www.tacomaworld.com/threads/2024-tacoma-owners-manual-maintenance-booklet.819465/