[throwaway85825]

Of course, but mostly it's just recirculation that causes costly engine rebuilds. If it wasn't so expensive no one would delete.

Most regulations target emissions at point of sale but don't give a toss if such systems are practical or maintainable. It's sometimes better for the environment to have more emissions but not so much waste from having to buy a new thing more frequently.

[rconti]

I've got a 2011 BMW X5 diesel with 189k miles on it. The DPF went out at around 150k, which is roughly the expected lifetime from my understanding. The part alone is ~$4000. Regardless of living in CA, I'd have replaced it anyway because I think it's the right thing to do. (I didn't want a non-DPF diesel that was emitting lots of PM2.5s when I made my purchase).

That said, many people would prefer the money in their bank account. And if I had decided to sell it rather than fix, no doubt it would have gone to someone looking to delete the DPF.

[thijson]

The diesel particulate filter (DPF) forces the engine to burn more fuel periodically in order to burn off the particles in the filter. The net result is more CO2 than would be produced ordinarily.

I watched some farming videos, and the farmers calculate the hourly cost of their combine, it's in the 100's of dollars per hour. They hate it when the engine goes into the regen cycle, and they are forced to let the engine run.

[SigmundA]

No the DEF systems tend to break down and its mandated the engine go into limp mode when they do, this is hated by those that do not care for emissions and one of the biggest reason to delete by truckers. Also costly to fix the systems out of warranty.

You can find instructions on how to make DEF simulators using raspi's to fool the ECU into think the DEF system is working, people who do care about emissions will still carry these for emergency so they continue on their trip and get to a shop later. The derate was over zealous for sure and was a bad policy.

Also DPF is a performance issue since it blocks the exhaust to some degree, same with catalytic converter with def nozzle so no its not just EGR at all. DPF also consumes more fuel for regens.

2027 diesel regulations was to mandate even more NOx control but also specified manufacturers were required to have 100,000 mile 10 year warranty on emissions systems, its 5 year, 50k now. I believe thats dead in the water now.

A diesel engine with a deleted SCR system puts out 40 times the NOx of a working one. Thats 40 trucks going down the road to 1 equivalent. NOx causes asthma and acid rain, its not for the environment as much as for you directly.

[throwaway85825]

And what percent of diesel emissions are from diesel passenger vehicles?

Emissions reduction efforts would be better spent ensuring repairability. The sunk cost emissions of landfills filled with junk created by planned obsolescence is much worse.

Diesel pick ups are not practical vehicles. Let's be honest, it's a hobby. It's always going to be niche and cutting down the last 10% is always the hardest. General aviation still uses lead.

[SigmundA]

Not sure what your point is, I was talking primarily about Class 8 heavy duty commercial trucks (semi) and other medium duty commercial use.

All the stuff that makes up emissions gear is highly recyclable and in fact some of it very desirable which is why people are getting catalytic converters stolen. So I do not worry about it filling up a land fill.

I also don't worry about EV batteries filling landfills because again they are very high grade ore for new batteries, once we have enough in circulation we no longer need to mine much lithium or rare earth.

I agree it should be reliable and repairable and forcing the manufacturers to have very long warranties on it seems like a good way to do that, having followed the various generations of DEF systems for the last decade the manufacturers have been making big strides because it costs them otherwise and has.

I also think airplanes using lead is stupid, but that is a fraction of even private diesel pickup usage let alone commercial trucking. Diesel pickups are at least 10% of all pickup sales now days.

[throwaway85825]

It's not that you cant recycle emissions equipment, it's that mechanically totalling and landfillimg cars once they hit 10 years old and are no longer supported by the OEM is stupid and environmentally detrimental.

Take appliances for example, the government basically mandates that they're energy efficient but the new linear compressors break. Cars got more efficient by tightening tolerances. There's always going to be an engineering tradeoff between reliability and efficiency. I just think the environmentalist types have been laser focused on creating efficient by non durable products that fill landfills.