The volume of the tank on your A4 Saloon is 12L.
In case the remaining AdBlue® mileage reaches 1500 miles, a warning is displayed on your dashboard. A alarm is heard to warn you. Below the 650 miles threshold, the AdBlue® warning is visible on the dashboard, a signal sounds and a message is displayed and three alarm signals echo. To turn off the AdBlue® warning when the tank is empty, pour at least 5,7L of AdBlue® in the tank.
If your warning shows a remaining mileage of 0 miles, restarting your car is impossible once the engine has been turned off. If your engine is still running and your tank is empty, it is still possible to drive to a petrol station. If the car does not start after the AdBlue® top up, wait for two minutes for the system to detect it. If the AdBlue® tank is empty, turn the ignition on for about 15 seconds and then start the engine.
This information can vary on some vehicles of the same model in relation to the options chosen by the manufacturer.