New details are starting to emerge about the 2014 BMW X5 and X6.

According to Automobile, the crossovers are being developed with a focus on improving fuel efficiency and reducing emissions. As such, the models will adopt new axles that weigh 330 pounds (150 kg) less than the current ones. This, combined with other weight saving measures, could allow the entry-level X5 to tip the scales at less than 4,000 lbs (1,814 kg).

Besides going on a diet, the redesigned models are slated to feature a variety of fuel-efficient engines. The magazine reports the usual six- and eight-cylinders will be joined by two four-cylinders - one petrol, one diesel - that produce 245 PS (180 kW / 242 hp). Additionally, plug-in hybrids are expected with a 350 PS (257 kW / 345 hp) inline-six and a 110 PS (81 kW / 108 hp) electric motor.

The M variants will also go eco-friendly as they are expected to be 10-15% more efficient than today's models. Despite this, the crossovers will reportedly retain the 4.4-liter twin-turbo V-8 with an increased output of 565 PS (416 kW / 557 hp).

On the styling front, the X6 will reportedly adopt a more functional design that will improve rearward visibility and increase rear passenger headroom.

Inside, the cabins are expected to be inspired by the 5-Series GT and should offer niceties such as leather upholstery, wood trim, a panoramic moonroof and power-operated rear seats.

The X5 could be unveiled at the 2014 North American International Auto Show, with the X6 following six months later.

Note: 2011 BMW X5 pictured

Gallery: 2014 BMW X5 & X6 come into focus

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