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Non-diesel vehicles don't pollute much if at all while idling. If we could get rid of diesel from commercial vehicles air quality would dramatically improve.
by ars 5y ago
Non-diesel vehicles don't pollute much if at all while idling.
If we could get rid of diesel from commercial vehicles air quality would dramatically improve.
- amluto 5y agoOnly when warm. Many modern gasoline burning vehicles are extremely stinky when cold. As I understand it, they deliberately run rich when first started to help heat up the catalytic converter, and I wonder if this is a case of optimizing for the wrong thing. EVs are, of course, emission-free when idle. (Although, oddly, at least some Teslas still can’t open or close their windows when in the off-ish state.)
- LegitShady 5y agoMy understanding of the cold-rich start was not anything to do with the catalytic converter. Cold air is more dense and contains more oxygen. At the same time, when the engine is cold gasoline is harder to vaporize and doesn't vaporize properly, and also can condense on cold engine parts. Running rich while the engine is cold allows additional gas to offset both of those issues. When the extra un-combusted gasoline passes through, a secondary air injection system allows the fuel to be burned up before reaching the catalytic converter and does heat it up faster, but this is a secondary benefit rather than the primary benefit.
- theodric 5y agoMy 23-year-old V12 7 series has electrically heated catalytic converters for this very reason. Thanks to those, according to German regs it qualifies as a ULEV! I think it still stinks at first start. Also, the cats cost two grand each to replace and the car requires a second battery to power them without draining the main starting battery so much that the car won't turn over. That's probably why we don't see more of this...
- ars 5y ago> Only when warm. In that case you should prefer idling, rather than stopping the motor and letting it cool down.
- 2143 5y agoThe reason for diesels on commercial vehicles is the massive amount of torque they produce low down the rev range. Useful for pulling heavy loads. I think the newer ones with the AdBlue tech prevents the soot from getting out.
- Godel_unicode 5y agoA really good way to generate lots of torque from a stop is an electric motor. You could use a combination of gasoline motors at speed with electric to start to get this same combination.
- earleybird 5y agoAs demonstrated by the Koenigsegg Gemera and its use of electric motors and an ICE. [0] [0] https://www.youtube.com/watch?v=W39yEt4R-SU https://www.youtube.com/watch?v=W39yEt4R-SU
- 2143 5y agoSure I agree electric engines produce even more torque. Just give it a few years for the whole thing to be economically viable and for them to convert their diesel trucks to EV trucks.
- User23 5y agoHence diesel-electric locomotives. Those things produce serious torque. I wonder if that technology could be usefully adapted to commercial trucks.
- seanmcdirmid 5y agoDiesel electric locomotives have a much worse idling problem than diesel ICE vehicles, you can’t just shut the turbine down without consequences, especially in winter, so they just idle for hours. See for example https://www.saferail.ca/blog/2019/7/3/idling-of-diesel-engines-rail-and-reason-the-dumbing-down-of-smartstart https://www.saferail.ca/blog/2019/7/3/idling-of-diesel-engin...