5 ms·

Part of the problem is that basically the closer you run the diesel engine to its optimum mpg-wise, the more NOx it emits. So, when you are trying very hard to

by lb1lf 10y ago

Part of the problem is that basically the closer you run the diesel engine to its optimum mpg-wise, the more NOx it emits. So, when you are trying very hard to make engines more efficient to get impressive mpg numbers, you also end up generating more NOx (Which you can then get rid of using urea, which I think is the preferred option in trucks and buses - think AdBlue or whatever it is called when used for cars.

PythonicAlpha 10y ago
The other part is, that producing cleaner Diesel cars is just more costly -- that was the main reason for VW to cheat.
- lb1lf 10y ago
  I wonder how my old diesel (1998 Toyota Land Cruiser 1KZ-TE, 3.0l I4 TDi) would fare when compared to a modern diesel. Obviously, it would soot orders of magnitude more - but I wouldn't be surprised if the NOx emissions were surprisingly low, seeing as efficiency was way down on Toyota's list of requirements; they just made a bigger fuel tank. It was designed to just work(tm) - almost regardless of what happened to it. Gas mileage? Not as much.
- raverbashing 10y ago
  Not really However it does consume more AdBlue and/or produces less power the cleaner it is They did it to sell a "better car" with disregard to pollution regulation
  - CydeWeys 10y ago
    > However it does consume more AdBlue and/or produces less power the cleaner it is This is why it's more costly. In order to design a diesel car that meets the exact same specifications, they either need to add an entire urea system (costs more money to manufacture, plus ongoing AdBlue costs to the consumer) or add a larger less efficient engine to meet the same performance target (costs more money to manufacture, plus ongoing higher petrol costs to the consumer). Making a non-polluting diesel car is certainly more costly than making an equivalent diesel car that you don't care about pollution on at all. You're adding a big engineering constraint, of course it gets more costly! I should add that I'm all in favor of cutting down pollution, and that if diesel as a technology turns out to not be that practical anymore for small cars, then so be it. Eventually they should all be zero emissions anyway.
    - raverbashing 10y ago
      Thanks for the clarification
    - jsz0 10y ago
      > if diesel as a technology turns out to not be that practical anymore for small cars, then so be it. This is tricky because, in the US market at least, one of the major appeals of small diesel cars was their performance / low end torque. There aren't really any other options on the market right now that can offer the same mix of performance/efficiency. Diesel cars are definitely on their way out in the US but I'm not sure it will be a net gain in the end. Lots of people such as myself are choosing to replace their small diesel cars with bigger, less efficient, similar performing cars.
      - hx87 10y ago
        Gasoline TDI comes pretty close in terms of performance and low-end torque, although fuel economy isn't as good. I wish OEMs would implement water injection as a standard feature in those engines, which would significantly close the gap.
      - Gibbon1 10y ago
        > major appeals of small diesel cars was their performance / low end torque. Friend of mine is ditching his VW Diesel TDI for a Chevy Bolt at the end of the month. I'll be interested to see what he makes of that switch. Electric has if nothing but low end torque.
Xylakant 10y ago
One problem with AdBlue is that the car makers decided that the car owners were not supposed to refill it, it was considered more like an oil change than a fill-up. So the tank needs to be large enough to cover a full maintenance interval - which either requires quite a large tank or creative solution to limit consumption. And - meh - the decision was made to limit consumption.
- lb1lf 10y ago
  I think - mind, think - that car makers may be innocent in this particular instance; I am pretty sure I read some time ago (Just as Dieselgate blew up) that regulations required AdBlue to be refilled primarily by workshops - this as it directly affected the emissions of the vehicle, and as such shouldn't (couldn't?) be entrusted to Joe Q. Public to do. However, at least around here they sell it at (some) gas stations, and the user manual (2012 Passat 3c) shows how you go about topping it up, so it can't be that much of a concern.
  - hydrogen18 10y ago
    Just another step to the complete infantilization of citizens by the government. If you can't pour a liquid into another container, you have no business being outdoors.
    - mikeash 10y ago
      I will note that about 13 million Americans already live in states where it's illegal to pump your own gasoline.
      - jessriedel 10y ago
        Yes, and this does in fact infantalize people. But it's an unintended consequence of it's functional purpose: job creation (regardless of the stated justification for the law).
      - vkou 10y ago
        That's a jobs program.
amcuit01 10y ago
Very relevant 33c3 talk: https://www.youtube.com/watch?v=CCu8XIHjKwc https://www.youtube.com/watch?v=CCu8XIHjKwc This all sounds to be entirely due to inadequate emissions testing processes and manufacturers doing the absolute bare minimum to comply with those tests as if they're gaming the rules of an automobile race.

by lb1lf 10y ago

PythonicAlpha 10y ago

The other part is, that producing cleaner Diesel cars is just more costly -- that was the main reason for VW to cheat.

lb1lf 10y ago
I wonder how my old diesel (1998 Toyota Land Cruiser 1KZ-TE, 3.0l I4 TDi) would fare when compared to a modern diesel. Obviously, it would soot orders of magnitude more - but I wouldn't be surprised if the NOx emissions were surprisingly low, seeing as efficiency was way down on Toyota's list of requirements; they just made a bigger fuel tank. It was designed to just work(tm) - almost regardless of what happened to it. Gas mileage? Not as much.
raverbashing 10y ago
Not really However it does consume more AdBlue and/or produces less power the cleaner it is They did it to sell a "better car" with disregard to pollution regulation
- CydeWeys 10y ago
  > However it does consume more AdBlue and/or produces less power the cleaner it is This is why it's more costly. In order to design a diesel car that meets the exact same specifications, they either need to add an entire urea system (costs more money to manufacture, plus ongoing AdBlue costs to the consumer) or add a larger less efficient engine to meet the same performance target (costs more money to manufacture, plus ongoing higher petrol costs to the consumer). Making a non-polluting diesel car is certainly more costly than making an equivalent diesel car that you don't care about pollution on at all. You're adding a big engineering constraint, of course it gets more costly! I should add that I'm all in favor of cutting down pollution, and that if diesel as a technology turns out to not be that practical anymore for small cars, then so be it. Eventually they should all be zero emissions anyway.
  - raverbashing 10y ago
    Thanks for the clarification
  - jsz0 10y ago
    > if diesel as a technology turns out to not be that practical anymore for small cars, then so be it. This is tricky because, in the US market at least, one of the major appeals of small diesel cars was their performance / low end torque. There aren't really any other options on the market right now that can offer the same mix of performance/efficiency. Diesel cars are definitely on their way out in the US but I'm not sure it will be a net gain in the end. Lots of people such as myself are choosing to replace their small diesel cars with bigger, less efficient, similar performing cars.
    - hx87 10y ago
      Gasoline TDI comes pretty close in terms of performance and low-end torque, although fuel economy isn't as good. I wish OEMs would implement water injection as a standard feature in those engines, which would significantly close the gap.
    - Gibbon1 10y ago
      > major appeals of small diesel cars was their performance / low end torque. Friend of mine is ditching his VW Diesel TDI for a Chevy Bolt at the end of the month. I'll be interested to see what he makes of that switch. Electric has if nothing but low end torque.

Xylakant 10y ago

One problem with AdBlue is that the car makers decided that the car owners were not supposed to refill it, it was considered more like an oil change than a fill-up. So the tank needs to be large enough to cover a full maintenance interval - which either requires quite a large tank or creative solution to limit consumption. And - meh - the decision was made to limit consumption.

lb1lf 10y ago
I think - mind, think - that car makers may be innocent in this particular instance; I am pretty sure I read some time ago (Just as Dieselgate blew up) that regulations required AdBlue to be refilled primarily by workshops - this as it directly affected the emissions of the vehicle, and as such shouldn't (couldn't?) be entrusted to Joe Q. Public to do. However, at least around here they sell it at (some) gas stations, and the user manual (2012 Passat 3c) shows how you go about topping it up, so it can't be that much of a concern.
- hydrogen18 10y ago
  Just another step to the complete infantilization of citizens by the government. If you can't pour a liquid into another container, you have no business being outdoors.
  - mikeash 10y ago
    I will note that about 13 million Americans already live in states where it's illegal to pump your own gasoline.
    - jessriedel 10y ago
      Yes, and this does in fact infantalize people. But it's an unintended consequence of it's functional purpose: job creation (regardless of the stated justification for the law).
    - vkou 10y ago
      That's a jobs program.

amcuit01 10y ago

Very relevant 33c3 talk: https://www.youtube.com/watch?v=CCu8XIHjKwc https://www.youtube.com/watch?v=CCu8XIHjKwc This all sounds to be entirely due to inadequate emissions testing processes and manufacturers doing the absolute bare minimum to comply with those tests as if they're gaming the rules of an automobile race.