DEF performance claims

How do chemical reactions taking place only in the exhaust system cause improved engine performance and lower maintenance?

 

Over the years, I've heard that claim from a number of places. Things like lower maintenance, more time between oil changes.

I wonder too ... do diesel locomotives use DEF?

Eleanor Weiss

 

Eleanor Weiss

 

Here's one place the claims are made:

https://www.discoverdef.com/def-overview/

"SCR is a so-called "aftertreatment" technology,
which means that it destroys harmful emissions
after combustion. This gives manufacturers
greater scope to tune engines to improve fuel
efficiency and increase power. Owners of SCR
vehicles enjoy greater reliability and longer oil
change intervals, which add up to impressive
operating cost savings over the life of the
vehicle."


Looking carefully, it seems the claims are not that the DEF itself improves things, but that if a manufacturer can depend on DEF being used, the manufacturer can alter the engine design to bring about the improvements.

Apologies - apparently that's what I've heard from time to time and it didn't sink in.

Eleanor Weiss

 

So, does anyone know if diesel locomotives are required to use DEF? Or diesel farm equipment? Or diesel boats?

Eleanor Weiss