Originally Posted by 1project2many

Diesel makers seem to have settled on the SCR as the best means of cleaning exhaust emissions. Anyone who's dealt with diesel EGR systems recognizes the maintenance involved long term in keeping these systems effective. Additionally, meeting current diesel emissions standards with an EGR strategy is becoming more and more difficult.

However, there are already stories of high costs and unexpected maintenance needed for the converters and associated particulate filters. My opinion is that this technology as it applies to vehicles is still in development and many people will learn the hard way what is and is not acceptable in maintenance and operation.

Now, as someone that appreciates a good bit of irony, I wish to point out that DEF is urea, a component of urine. However, the urea we buy in a bottle of DEF is synthetic because the process of removing urea from urine is much slower than manufacturing it. So, not only have engine manufacturers begun selling us urine for our cars, but they're arguing that our own urine is not good enough to use and they must make it for us.