BMW AG will announce at the North American International Auto Show in Detroit this month plans to market a pair of diesel-powered models in the U.S. – the X5 xDrive 35d cross/utility vehicle and 335d coupe.

The German auto maker also reveals a production version of the BMW X6 Sport Activity Coupe and a production 1-Series convertible. Both vehicles are due in the U.S. in late spring.

BMW first announced plans to bring one of its vaunted diesel engines to the U.S. at the Detroit show in 2007, and speculation over its application has run high.

The ’09 X5 xDrive 35d and 335d arrive this fall with the auto maker’s 3.0L inline 6 cyl. twin-turbo diesel engine. The engine leverages a urea-injection exhaust treatment, which BMW calls BluePerformance, to meet 50-state emissions requirements.

The auto maker says the diesel develops 265 hp, a whopping 425 lb.-ft. of torque (576 Nm) and will push the X5 xDrive 35d from 0-62 mph (100 km/h) in 7.2 seconds while still achieving 19/25 mpg (12.4/9.4 L/100 km). It powers the 335d from 0-62 mph in 6.2 seconds and gets 23/33 mpg (10.2/7.1 L/100 km).

BMW will release pricing closer to the launch date of the vehicles, which arrive ahead of more stringent fuel-economy laws that begin in 2009.

The auto maker also will reveal a production version of its BMW X6 Sport Activity Coupe, which will go on sale in the U.S. in late spring of 2008 as an ’08 model. It arrives as an X6 xDrive35i with the company’s 300-hp, twin-turbo 3.0L I-6 engine and as an X6 xDrive50i with a new 400-hp, 4.4L twin-turbo V-8 engine.

The BMW Concept X6 ActiveHybrid that premiered in Frankfurt in September will make its first North American appearance at Detroit. The vehicle leverages a 2-mode hybrid drivertrain, but BMW promises far better driving dynamics than typical hybrids. It also expects a 20% reduction in fuel consumption vs. a comparable gasoline vehicle.

A production version of the BMW 1-Series convertible will occupy the stage in Detroit, as well. Its U.S. launch will follow the introduction of the 1-Series coupe by several months. As with the coupe, BMW will offer the convertible as both a 128i equipped with a 230-hp Valvetronic I-6 engine and a 135i featuring a 300-hp, twin-turbo 3.0L I-6 engine.