Running out of AUS32 is not like running out of washer fluid. On an SCR vehicle the engine itself reacts.
The warning sequence
On most SCR vehicles the system warns you well before the tank is empty. The usual pattern is:
- Low-level warning: a dashboard light or message with the remaining range.
- Countdown: repeated warnings that tell you how many kilometres or restarts you have left.
- Power reduction: the engine limits torque and speed (often called “limp mode”) to push you to refill.
- No restart: on many models, once the engine is switched off it will not start again until DEF is added.
The exact behaviour depends on the manufacturer and model, so check your manual. The point is the same: the vehicle is designed not to run for long without DEF.
What to do
- Refill as soon as the first warning appears. A 10-litre canister is usually enough to clear a low-level alert.
- Keep a spare canister in the vehicle, especially on long routes and for work vehicles.
- After refilling, some vehicles need the ignition on for a short time before the warning clears.
What not to do
- Do not put DEF in the diesel tank, and do not put diesel in the DEF tank. Both can cause serious damage. If it happens, do not start the engine and call a workshop.
- Do not dilute it with water. The concentration is what makes the system work, and the vehicle can detect a wrong mixture.
- Do not use “emulators” or switch the SCR off. This is a shortcut that increases emissions, can damage the vehicle and may be illegal.
For fleets: tracking DEF consumption together with diesel is a simple way to spot problems early. If DEF use suddenly drops, the SCR system may need a check.
Keep stock, not surprises
Fleets and stations that buy in 1000-litre IBC tanks avoid emergency top-ups and pay less per litre than with small canisters. BluVera delivers 10L canisters and 1000L IBC tanks across Albania.