 The production XJ220 used a 3 @.@ 5 @-@ litre ( <unk> cc ) twin turbocharged engine , which was given the designation Jaguar / TWR JV6 . This engine , which replaced the Jaguar V12 engine featured in the concept car , was a heavily redesigned and significantly altered version of the Austin Rover V64V V6 engine . The decision to change the engine was based on engine weight and dimensions , as well as to environmental emission considerations . Use of the shorter V6 engine design allowed the wheelbase of the XJ220 to be shortened and its weight to be reduced ; the V12 engine was definitively ruled out when it was determined it would have difficulty in meeting emissions legislation whilst producing the required power and torque . 
