Apparatus and method for determining a viscosity of a liquid as well as the internal combustion engine

According to the invention, an apparatus for determining a viscosity of a liquid is provided. The apparatus comprises a conduit for example, to transport the liquid. The device further comprises a first determining unit for determining a first pressure difference of the fluid between a first pressure at a first location in the conduit and a second pressure at a second position on the line. In addition, the apparatus comprises a second detection unit which is configured for detecting a second pressure difference of the fluid between a third pressure at a third position in the line and a fourth pressure at a fourth position in the line.