The paper presents a new development of a low-noise passenger car and small truck diesel engine. As described in the first section of this contribution the new design concept is mainly characterized by the vibration isolation between the vibration excited internal engine structure and the external engine casing, obtained by elastic elements specially developed for this purpose. The external engine casing and the flywheel housing are designed as one part where the gear box can be bolted on in the usual way. An essential part of the paper is dedicated to the description of preliminary theoretical and experimental investigations into the design of the vibration isolating elements between the so-called crankframe and the external housing and to the description of the design of the external housing. In the following the test results gained on a prototype engine featuring the mentioned design principle are discussed. This prototype engine is a water-cooled 2.2 liter diesel engine. The last section finally proves that particularly good results with regard to economic viability can be achieved by using engines of the above design in different vehicles, such as cars, small trucks and farm tractors.