The XUD was available with either SOHC or 12-valve DOHC heads. It was mainly applied transversally in front wheel drive vehicles, tilted by 30°. However, some applications in non-PSA vehicles had the engine installed longitudinally, with rear wheel drive.
Displacement ranged between 1769 and 2138 cc, and all XU diesel engines had a stroke of 88 mm (3.5 in) or 92 mm (3.6 in). The former was shared with the XU9. Bore sizes ranged from 80 mm (3.1 in) to 86 mm (3.4 in), some shared with other XU engines.
Upon its release the engine was noted as one of the best Diesel engines (for cars and light vans) in the world with its high power output and refinement it made all other diesel engines seem agricultural . However if the cooling system is neglected (or improperly bled after filling) the engine had a tendency to blow its head gasket; coolant changes on this engine are critical.
The engine when accompanied by a Bosch fuel pump can run on SVO (pure vegetable oil). The viscosity of vegetable oil when cold is too great for rotary injection pumps (in particular the weak Lucas pumps), preventing it acting as a lubricant and seizing up the distributor/rotary injection pump. In order to reduce the viscosity of the SVO it should be heated to engine coolant operating temperature, typically with a two tank system on order to start and shutdown on diesel or bio-diesel.
|XUD7 T/K||78 PS (76 hp/57 kW)||Diesel turbo|
|XUD7 TE||90 PS (88 hp/66 kW)||Diesel turbo with intercooler|
|XUD7/K||60 PS (59 hp/44 kW)||Diesel|
|XUD7/Z||60 PS (59 hp/44 kW)||Diesel catalyst|
|XUD9||65 PS (64 hp/47 kW)||Diesel|
|XUD9 A||71 PS (70 hp/52 kW)||Diesel|
|XUD9 TE/L||92 PS (90 hp/67 kW)||Diesel turbo|
|XUD9 TE/Y||90 PS (88 hp/66 kW)||Diesel turbo catalyst|
|XUD9/Z||68 PS (67 hp/49 kW)||Diesel catalyst|
Both were 12-valve SOHC engines with a 92 mm (3.6 in) stroke. The naturally-aspirated XUD11 A was bored to 86 mm (3.4 in) for a total displacement of 2.1 L (2138 cc), while the turbocharged ATE/BTE versions were reduced in bore to 85 mm (3.3 in) for a total of 2.1 L (2088 cc).
|XUD11 A||83 PS (81 hp/61 kW)||Diesel 12-valve SOHC|
|XUD11 ATE||110 PS (108 hp/80 kW)||Diesel 12-valve SOHC turbo|
|XUD11 BTE||110 PS (108 hp/80 kW)||Diesel 12 S turbo catalyst|