E24s produced after June 1987 were fitted with ellipsoid headlamps, as per the recently introduced E32 7 Series.[23] The front and rear spoilers were redesigned, with a single design used worldwide[24] (prior to this, models sold in the US used a different design to the rest of the world).
The 635CSi engine was updated to the higher compression M30B35,[25] which resulted in a power increase of 19kW (25hp) for engines with catalytic converters
In 1985, the 633CSi was replaced by the 635CSi for the North American Market.[28] This model used the M30B34 engine, which produced 182hp (136kW) and 214lbf⋅ft (290N⋅m) at 4,000 rpm. An L6 "luxury edition" version of the 635CSi was available in North America for the 1987 model year. The L6 featured leather headliner and trim and an automatic gearbox.[29]
In 1988, the engine was upgraded to the M30B35. This engine has a capacity of 3.4Litres (despite the model code and the "3.5" inscribed on the intake manifold) and produces 208hp (155kW) and 225lbf⋅ft (305N⋅m) torque. This upgraded engine resulted in United States models (with catalytic converters) offering similar performance to European models.[28] Self-levelling rear suspension was added to the 635CSi and M6 features list.[