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Comment by SideburnsOfDoom | Hacker News Reader

For instance, For a long time diesel has promoted in Europe as greener than petrol. This is soon to change, because: https://www.theguardian.com/uk/2013/jan/27/diesel-engine-fum...

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Diesel engines produces less CO2 by being slightly more efficient.

Pretrol engines produce less nitrogen oxides and particulate matter.

What's "greener" is just a matter of your definition of it.

> What's "greener" is just a matter of your definition of it.

What i means was that the "promoted" part is soon to change, because of the greater understanding of the drastic public health consequences.

Diesel /is/ greener when you consider only CO2 emissions and energy efficiency, although turbocharged direct injection engines narrow that gap significantly. If this were the '70s though, I'd much rather have a fleet of diesel cars running around than ones with cabureted gasoline engines.

What about all the people who die from diesel particulates? Failing to consider that is exactly the mistake Europe is still making.

Particulates are easy to deal with using current technology--burn lean, burn hot (and inject lots of urea to get rid of all the NOx that this regime creates), and stick on a filter on the tailpipe to get rid of the stuff that does get created. The main problem is that diesel engines last forever, and a lot of old engines that don't meet requirements are still on the road.

This is partly true: You can reduce particulates, but they're still bad in areas with a lot of less-emitting vehicles. Also, the technology that reduces particulates needs to be carefully maintained to continue working as well as it did the day the vehicle left the factory... and there's plenty of incentive to cheat, in order to save money.

With 2016 diesel technology, the only "less-emitting vehicles" are EVs and possibly CNG-powered vehicles. As for cheating, as long as the manufacturer does its job (by either eliminating EGR altogether or installing a catch can in the PCV system), there is little to no incentive to cheat on the operator's part. Urea is dirt cheap as long as you don't buy from the dealership.

I was comparing modern diesels to older ones, was that unclear? It's not difficult to get enough 2016 diesels in an area small enough to violate the short-term standard for particulates. And I'd bet your confidence about cheating is misplaced; time will tell.

Try riding a bike behind a bus or truck with a poorly maintained diesel

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