A year ago I was working in Ford's engine dyno lab working on the DEF systems. |Then, worked at JMT testing doing catalyst development. It is exactly that, Diluted Pig urine is what is going to be used. It doesn't increase fuel economy, it removes emissions from the exhaust. The system injects urea after the DPF and removes almost all the NOX and THC. But, then you now have to have an ASC, (ammonia slip catalyst) to remove the ammonia caused by the urea. You are correct about the vehicle going into a type of limp mode until you fill it. BUT, like every other system before it, it can be eliminated and turned off in the calibration.
On a side note, now that ALL diesel vehicles(semi's, construction machinery, and anything else with a diesel), I would expect the price of pork products to increase as it benefits the pig farms to not slaughter their pigs and have them continue to produce urine that the government is requiring vehicles to now use. I have been waiting for these systems to reach vehicle production and see what happens.
Something else I just remembered about the urea injection........the urea solution leaves a really shitty mess if you spill it. It creates a white film of crystallized residue on everything.
