DEF performance claims

Farm equipment uses DEF

 

Farm equipment is yes.
Off road equipment (construction vehicles) is yes, or soon. Not sure the requirement date.
Trains.. maybe. Smaller high speed passenger teains yes, bigger locomotives no.
Now here's the kicker. DEF is not required anywhere. What is required is Tier 4 emissions compliance. Semis and other "smaller" diesel engines use DEF as a way to meet Tier 4. Locomotives use other means to achieve Tier 4.

 

I'm not a mechanic. I don't even pretend to be one. I'll pass along our shop manager's thoughts on DEF instead.

Do not run with DEF below 1/2 tank as between 1/2 & 1/4 tank air can get sucked into the system and cause damage.

Like I said, I don't know.

 

If you can substitute SCR in place of EGR (which is starting to happen), then yes, it totally increases reliability and extends service intervals.

Imagine how much better these modern engines would be if they weren't choking on their own exhaust?

 

I heard one person say if a driver attempts to run without DEF, the engine will "barely run."

From what has been posted here, that might be caused by sensors responding to the lack of DEF?

Eleanor Weiss

 

No, the railroads are almost totally exempt from ANY emissions requirements until just recently. They, and the regulatory agency that is supposed to over see them, the FRA(Federal Railroad Administration) have a tacit agreement to allow the railroads total freedom in this regard.
In the event you would like to know how the railroads really feel on this topic:

A Major but Little-Known Supporter of Climate Denial: Freight Railroads

 

It will barely run because the computer is putting it in limp mode. Diesels put out a lot of nitrogen oxide. DEF gets injected to reduce it. As far as the engine itself is concerned, it doesn't give a crap about what's coming out the tail pipe, as long as there's no restrictions. So lack of DEF does nothing at all, as far as the engine cares. This is mandated by the government to reduce emissions, so you get forced into limp mode until the "problem" gets taken care of. As long as the DEF meets the right purity and quality, none of it can improve performance, because it's getting injected into the exhaust.

If you are on the drag strip, and you shoot nitrous into the engine, do you get a performance increase? Yep. Now inject that nitrous into the exhaust pipe. Performance increase? Of course not. But what if you buy a more expensive brand of nitrous and inject it into the exhaust pipe. Performance increase? Of course not.

Now could one brand of DEF allow your sensors and pump to last longer, thereby keeping your uptime higher? Maybe. I don't know the answer to that. If so, I guess you could say it indirectly increased performance by reducing downtime. But if that were the case, then the mega companies would all be running the same DEF, instead of using whatever is at the pump. Why do they use whatever is at the pump? Because DEF is DEF.

 

I've said this before. There are parameters you can change with the DDDL software that define what happens when your truck derates. Instead of being limited to 55, 45, then 5 mph you can set it to 99, 98, and 97. There is also an acceleration limit that defaults to .5 kph, which means it will take about 30 seconds to accelerate 10 mph. You can change that to a higher number as well. The DEF light will still be on and the CEL and MIL lights will still be on, but you won't need a tow.

 

Fascinating! Thanks to all who replied!

Eleanor Weiss