3 ms·
I don't know much about this topic, but according to http://www.popularmechanics.com/cars/a17430/ezra-dyer-volkswagen-diesel-controversy/ http://www.popularmech
by SandB0x 11y ago
I don't know much about this topic, but according to http://www.popularmechanics.com/cars/a17430/ezra-dyer-volkswagen-diesel-controversy/ http://www.popularmechanics.com/cars/a17430/ezra-dyer-volksw...
"All the other carmakers control diesel emissions by spraying a urea solution into the exhaust stream, where a catalyst converts it to ammonia"
and supposedly VW have omitted this mechanism to get diesel engines into their smaller cars.
- mzs 11y agoClarification: VW does employ SCR in some models and years, I believe starting with MY16 no US VW comes without it.
- jddaigle 11y agoIt was phased in on the bigger, heavier cars first. The current US-model Passat has used SCR since it was introduced, as has the Touareg with the and every other VW/Audi with the 3.0L V6 TDI. VW didn't put it in the Golf or Jetta until 2015 because it takes up room, adds cost and complexity. By 2015 emissions standards got tight enough that they had no choice. Prior to that the Golf and Jetta used a NOx catalyst that requires a periodic burn-off achieved by sending a pulse of unburned fuel down the exhaust. Same deal as the particulate trap--that stuff needs to be burned off every so often, too.
- rconti 11y agoStarting with MY16 no US VW TDIs are being sold because they never got their certificate of conformity from the EPA.