In this case, marine diesel engines which used to be famously long lived. The Detroit Diesel engines of old were famous for running 20,000 or 30,000 hours before a four day rebuild at the dock set them up for another 20,000 or 30,000 hours. You couldn't kill these engines. Rather, you would leave them to your kids in your will.
That's over now, and it's because of the EPA. Over a span of 15 or 20 years, they ratcheted up the emission requirements for these engines to the point that Detroit Diesel would be fined millions and millions of dollars for selling their old (famously reliable) design.
And so now you have to rebuild after 10,000 hours, and you have to replace three times as many parts. Plan on a month, rather than four days.
This is a very interesting video on the subject. While I'm not an expert on diesel engines, it certainly seems solid from an engineering perspective.
Here are the main points.
1. Pressures have gone from 10,000 psi to 30,000 PSI for a bunch of EPA-imposed constraints. This shortens the lifespan of parts used in the engines.
2. The higher pressure means that engines are much more vulnerable to bad diesel fuel: water particles or tiny flakes of rust now essentially sandblast the pistons, valves, and cylinders. This didn't used to take place at the old lower pressure. This sandblasting effect shortens part life even more, which makes engine rebuild and cost even higher.
3. Because parts will fail much more often now, manufacturers put all sorts of sensors in place. The sensors themselves can fail - the high seas is a notoriously unforgiving environment and salt water will get into the engine room. This causes corrosion, which triggers sensor faults. The engine's computer (itself a new thing, with software of questionable quality) will detect the fault and sometimes put the engine into "Limp Home Mode" - not allowing it to go above, say, 1000 RPM. A ship in a storm may find its engine dangerously under powered, putting at risk the lives on board and the safety of the ship itself. If a ship sinks in a storm under these circumstances, the fuel oil in the tanks will pollute the environment.
4. Not pointed out in the video, ocean-going vessels do not have to worry about emissions. From a pure regulatory perspective, that is. However, finding a new engine with all the design "upgrades" discussed here is the challenge. I don't know what EU regulations are, so maybe a MAN engine doesn't have to deal with this. But I'm nasty and suspicious and think that EU regulations could be even worse than EPA's.
Thanks a whole lot of nothing, EPA. You're supposed to protect the environment. Oh, and not get Americans killed.
The only thing I think is unfair about the video is the title. Engine manufactures design their engines to fail after 10 years because the EPA forces them to.
You could roll back all the environmental regulations since 1990 and shutter the EPA and this Republic would be a whole lot better off.
