Tatra used a 17.6 L (1,070 cu in) air-cooled naturally aspirated V12 diesel engine in many of their trucks; for instance, the Tatra T813 and uses 19 L air-cooled naturally aspirated or turbo V12 diesel engine in Tatra T815. Some large trucks have been fitted with twin V12s that drive a common shaft, although this is often advertised as a V24.