No engine is as controlled as a modern diesel. If it is using a SCR system with an AdBlue add-on, which according to the latest regulations will probably be down to the class of compact cars a standard, then the AdBlue range will perhaps be displayed near to the next service or refueling.

There is an uninterrupted message together with a signal tone in case of a blocking risk of the particle filter. Much earlier in the mileage is the same message with low level in the AdBlue tank. This starts at a range of below 2,400 kilometers, of course again with the appropriate acoustics. In addition, the range is displayed permanently.

Presumably there will be, as with driving on very low fuel level, manufacturers who will not allow any display other than this, may be not even the outside temperature. The warning symbol begins to flash from 600 kilometers remaining. Now the system becomes awkward, because a message appears after how many more kilometers you can not even start the vehicle, for example to the gas station or to the workshop.

By the way, manufacturers are sticking with this behavior to legal requirements. The system now requires a certain minimum amount. You can't fetch only two liters. Even harder is the case with faults in the exhaust system. You must even confirm the message to ensure that you have noticed it. Thereafter, e.g. still more than 1,000 kilometers are possible. But if nothing is done, the path to the workshop will probably be 'pickaback'.

The question is how to deal with the ban of a restart of the engine and the subsequent, cumbersome and costly transportation to the garage. The four-cylinder engines of VW, for example, in which an injector fails, can only be operated with a very limited function to protect the engine. This includes approx. 90 km/h, but only on the flat, difficult switching at a maximum of less than 2500 rpm. So no one drives around for a long time under this circumstances, but reaches the next workshop. And maybe the engine now is as low-emissioned as with AdBlue?