 With Freight Rover becoming part of Leyland DAF the 300 Series was superseded by the 400 Series, which also offered air suspension and a 2.5-litre Peugeot-sourced diesel engine (praised by contemporary reviewers for reliability, but changed later on for the Ford Di engine from the Transit which was described as 'superb' by reviewers).At this stage, it was given a new radiator grille, bearing the Leyland DAF badge.A low-compression version of the 2.0L O-Series petrol engine remained available (but was dropped in 1991 due to lack of demand), in addition to the 3.5L Rover V8 (pictured) which was popular with police and ambulance services, where it was often mated to a ZF 4HP22 transmission.