TURIN, Italy – Four years on the market and 1.4 million sales later, BMW redesigns its 5-Series range to improve aesthetics and functions and add cleaner engines.

The new-generation range, comprising sedan, touring and Gran Turismo models, reaches showrooms in Europe and most global markets in June, with U.S. sales launching in August as ’14 models.

The U.S. version of the 535d large sedan gets a new 3.0L inline-6 diesel engine with the nitrogen-oxide-reducing BMW BluePerformance technology now common to all of the auto maker’s new diesels and making 255 hp and 413 lb.-ft. (560 Nm) of torque.

The European configuration produces 300 hp and 465 lb.-ft. (630 Nm) of torque. Also in Europe, BMW will introduce, in the 518d, an all-new 143-hp 4-cyl. diesel with TwinPower Turbo technology and achieving 52.3 mpg (4.5 L/100 km) and carbon-dioxide emissions of 119 g/km.

A new V-8 gasoline engine with TwinPower Turbo technology develops 450 hp and 480 lb.-ft. (650 Nm) of torque.

In all, BMW offers six diesel and four gasoline powerplants for the new 5-Series Sedan and Touring models, including the M550d xDrive Sedan and Touring from its M Performance Automobiles sub-brand.

Topping the range is the BMW ActiveHybrid 5, which combines the 3.0L gasoline engine of the 535i with a 40-kW (54-hp) electric motor for 149 g/km of CO2 emissions and 36.2 mpg (6.5 L/100 km) in city driving in the EU combined cycle.

The refreshed 5-Series range, which will be sold as ’14 models, will be available with xDrive all-wheel drive.

Exterior design changes are subtle, with additional chrome trim here and there. A wider rear section features an expanded track and larger fenders. The Gran Turismo’s hood shows a stronger character and reflects BMW's quest for better aerodynamics.

The Gran Turismo also receives a 14% expansion of its luggage compartment, from 15.5 cu.-ft. (440 L) to 17.7 cu.-ft. (500 L).

Separately, sources tell WardsAuto the next evolution of the BMW X5 cross/utility vehicle and high-performance X5M will be revealed at the Frankfurt auto show in September.