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Comment by kbenson | Hacker News Reader

> One thing that all of the designs have in common is poor performance and piss-poor fuel economy.

At what point does it become economical to just run gasoline instead of diesel then (that is, manufacturers selling gasoline models)? If we are talking about diesel still being economical instead of gasoline, but just not as economical as when it was allowed to be more polluting, I'm not sure I can muster much sympathy (but I'm fairly uneducated on the subject, so it may just a matter of not knowing enough).

> When the EPA makes rules that result in dangerous and/or non-functional product designs

Did the EPA make rules that required that, or did manufacturers mess up in their attempt to offer the same features as before? Did the EPA dictate this solution, or did the market respond with a poor solution to an EPA requirement on emissions?

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> At what point does it become economical to just run gasoline instead of diesel then (that is, manufacturers selling gasoline models)? If we are talking about diesel still being economical instead of gasoline, but just not as economical as when it was allowed to be more polluting, I'm not sure I can muster much sympathy (but I'm fairly uneducated on the subject, so it may just a matter of not knowing enough).

People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds. They also make more low-end torque, for the same reasons. Both of these factors are extremely important to the types of equipment that you see diesels in, probably even moreso than the problems caused by diesels. For many years, Diesel fuel was more expensive than gas, but people kept running them anyway in the applications for which they were most appropriate. For cars, yeah, we'll probably just see the death of diesel in that space.

> Did the EPA make rules that required that, or did manufacturers mess up in their attempt to offer the same features as before? Did the EPA dictate this solution, or did the market respond with a poor solution to an EPA requirement on emissions?

The market responded with the only solutions it could come up with. The EPA made standards that are impossible to meet using any available technology without causing some or all of the problems I mentioned.

> The EPA made standards that are impossible to meet using any available technology without causing some or all of the problems I mentioned.

I think you're being hyperbolic here in saying that the standards are impossible to meet. What about urea injection? That works pretty well, right?

But even ignoring that, it's not like there's some god-given right to run diesel engines. Either the emissions standards are reasonable or they aren't. That's the only consideration here. If they are reasonable, and most diesels can't meet them, well then too bad, diesel is just an inferior technology. There's alternatives that don't find it impossible to meet environmental/health standards.

I don't think replacing "inferior technology" with inferior technology is a good idea.

I don't follow. What "inferior technology" (in scare quotes) is being replaced by what actually inferior technology? Are you really trying to claim that gasoline engines are inferior to diesel engines for passenger vehicles?

I don't think people / companies really have a 'right' to pollute, so as long as the standards are possible to meet at reasonable costs I don't see a problem.

PS: Low end torque is really just a transmission problem. X(1) power at Y(1) RPM > X(2) power at Y(2) RPM.

> People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds.

This makes plenty of sense for heavy machinery and trucks. This makes no sense for passenger cars, and little sense for most consumer SUVs and light-duty trucks. On any decent modern car a gasoline engine with proper maintenance is the about the last thing to go. How often does a typical car owner rebuild their engine? By the time you get to 200K, a car is typically a money hole for reasons having little to do with the engine. This goes double in northern climates with real winters. By the time the engine needs a rebuild you have a rust-bucket clunker that should be replaced with a more contemporary model.

>> People run diesels due to durability. They run at lower RPM than similarly designed gas engines, and last longer between rebuilds.

Reliability is one of these stubborn diesel myths that refuses to die. The lifespan of modern gasonline engines -when driven normally- is several multiples of what the average owner will drive the car for before it is replaced. You can easily put 300K kilometers on a gasoline engine before it needs a 'rebuild' (which typically involves not much more than changing the piston rings and rod bearings). Around 150K you may need a mild cylinder head revision (valve seals, valve seats, tappets) if you torture the engine enough. You won't have to break the bank for either of those. I don't know a single person except myself (driving a 25 year old car with a high-performance engine) who ever needed an engine rebuild.

Meanwhile, regular servicing for diesel engines is guaranteed to be more expensive compared to a gasoline engine, so in the long run you will not save any money on maintenance unless you drive your car without any care for reliability.

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