Which Adblue is the best for Audi?

In this blog, we will find out which Adblue is the best for Audi and answer the following questions: what are the components in the Adblue system in an Audi? What is the capacity of Adblue in Audi? How to refill Adblue in Audi? 

Which Adblue is the best for Audi?

The best AdBlue for the Audi is the Kruse bottle of Adblue/ Diesel emission fluid available at the authorized Audi Dealerships. The part number for the Adblue is G 052 910 A2, it complies with the ISO Standard 22241. Depending on the location there can be 1.89, 5, and 10 liters of Adblue containers available at the dealership. 

Adblue is a solution of urea and deionized water, it is also known as diesel emission fluid or AUS 32. The Urea percentage is between 31.8 to 33.0 percent and it is a colorless liquid with a hint of ammonia odor. The AUS 32 is used by all the Euro 6 diesel engines in Audi, in order to comply with the exhaust emission norms.

It is a non-flammable solution and very easy to store so it can be easily stored in the vehicle or in a suitable container inside a garage. Audi costumes are not obligated to buy Adblue from the dealerships. There are other places like automotive parts stores and gas stations that sell Adblue.

The only requirement is that the Adblue that is used for refill must be in a liquid state and it should comply with the ISO 22241 standard. If the concentration of the urea in the Adblue is not okay, the Adblue injection system will not function correctly and the vehicle will even show a warning message in the instrument cluster.

The cost of the Adblue can also vary depending on the location, consult the Authorized dealership for the details. The consumption of Adblue depends on the driving style and the quality of the diesel fuel in the vehicle.

What are the components in the Adblue system in an Audi?

The components in the Adblue system are as follows:

  • Adblue tank

The Adblue tank is located on the rear axle in Audi, the capacity of the tank is 25 liters. A level sensor and an electrical pump are part of the Adblue tank. The electrical pump is used to pressurize the Adblue lines and pump the Adblue.

The filler neck is located next to the diesel tank filler neck. There is no separate fuel filler lid. The cap of the Adblue tank needs the 17 mm spanner to unscrew, it cannot be unscrewed by hand. Adblue caps are always marked in blue color.

  • Adblue lines

Adblue lines are present between the Adblue fuel tank and the metering valve. It is made from rubber and the corrosive nature of the Adblue cannot damage the Adblue lines. The Adblue pump only works when the Adblue line is leak-tight, if there is a minor leakage then the Adblue leaking from the line will form white crystals near the area of the leaks.

  • Metering valve

The metering valve in the Adblue system is like an injector, the Adblue from the tank is injected into the exhaust system. Injection quantity depends on the actuation duration of the metering valve when the AdBlue is injected into the exhaust system; crystallization of AdBlue on the injector is normal.

It does not affect the injection process. The SCR or Adblue control unit determines the actuation duration of the metering valve. It is directly connected to the Adblue control unit.

  • SCR

Selective catalytic reduction is an important part of the Adblue as well as the emission control exhaust system. Audi also uses a diesel particulate filter to separate the unburnt hydrocarbons and soot particles in the exhaust gasses.

The AdBlue injected from the metering valve mixes with the exhaust gasses in the SCR. SCR has a honeycomb maze structure that acts as a catalyst and helps Adblue in breaking down the nitrogen oxides in nitrogen, water vapors, and a small number of carbon dioxides.

The upstream and downstream Nox sensors determine the percentage of nitrogen oxides before and after the SCR. The signal from the Nox sensors is used to determine the efficiency of the SCR and the exhaust gas emission control system.

  • Adblue control unit 

The Adblue control unit or the Adblue ECU is located under the rear seat or in the luggage compartment. It is connected to the Adblue pump, level sensors in the tank, and the Adblue metering valve. The signal from the NOx sensor is also recorded by the Adblue control unit.

If there is a warning in the instrument cluster related to the Adblue system, there will be a corresponding fault code stored in the fault memory of the Adblue control unit. The control unit must be reset after refilling the Adblue or performing repairs otherwise the fault message occurs even if the Adblue level is okay.

What is the capacity of Adblue in Audi?

The capacity of the Adblue tank in all Audi models is between 24 -26 liters. The quality is large enough to last for the service interval of the vehicle. However, the consumption of Adblue can increase the percentage of nitrogen oxides in the exhaust systems.

A minimum of 5.7 liters of Adblue is needed in the tank, if the level is below this; the Adblue control unit will show a message ‘Refill AdBlue, No restart in miles’. The remaining miles are calculated by the Adblue control unit depending on the driving style and the percentage of nitrogen oxides in the exhaust system.

If there is no Adblue in the tank then the vehicle will continue to operate for the ongoing driving cycle. Once the vehicle is switched off, the engine will not start till there is a minimum amount of Adblue in the system. 

How to refill Adblue in Audi? 

The process to refill the Adblue in Audi is given below:

  • Turn on the ignition and open the fuel lid.
  • Use the spanner to unscrew the AdBlue cap and place it on one side.
  • Place the Kruse bottle on the filler neck and rotate until the Adblue starts to pour into the tank.
  • Refill the tank with the appropriate amount, it is possible to check the Adblue in the instrument cluster.
  • Screw the cap back on after the refill is complete.


This blog gave information on the best Adblue for Audi and also explain the components of the Adblue system. Although Adblue is just a solution of Urea, it is highly corrosive on aluminum and painted surfaces. It can also cause irritation to the skin and eyes. Hence, used proper gloves when handling.