BMW has unveiled the second-generation X3 model at the Paris motor show.

It will be among the most economical and efficient mid-sized off-roaders on sale when it reaches the UK in January, the company claims.

See official pics of the new BMW X3 - plus the pics from the Paris motor show

The entry-level 181bhp, 2.0-litre manual X3 xDrive20d will offer combined economy of 50.4mpg and CO2 emissions of 149g/km. That trumps the Audi Q5 2.0 TDI 170 by 4.8mpg and 14g/km.

Set to be unveiled at the Paris motor show in October, the new X3 has been thoroughly re-engineered inside and out. But, once again, it is the new off-roader’s styling that’s sure to stir controversy.

Read Autocar's development drive of the new BMW X3

The X3’s exterior blends styling elements from the smaller X1 and larger X5 in a five-door body that has a familiar silhouette and, significantly, larger rear door apertures than the outgoing model for easier access.

The new off-roader has grown, but not by as much as was expected after the introduction of the more affordable X1. Length is up by 78mm to 4648mm, width decreases by an incremental 4mm at 1855mm and height rises by 14mm at 1675mm.

The wheelbase has also grown by 15mm to 2810mm, providing the basis for a 70-litre increase in luggage capacity to 550 litres.

Inside, there’s a new dashboard, multi-function steering wheel, revised seats and more elegant trims — all at a quality level on a par with the 3-series. BMW hopes that this will silence critics of the outgoing X3’s dowdy interior. Equipment levels have been improved, although UK pricing has yet to be fixed.

As well as the 181bhp 2.0-litre, four-cylinder diesel in the xDrive20d, BMW will introduce the new X3 with a 302bhp, 3.0-litre, turbocharged straight six petrol in a more luxurious xDrive35i range-topper.

The diesel will come with the choice of either a standard six-speed manual gearbox or an optional ZF-engineered eight-speed automatic. The xDrive35i will get the auto as standard, allowing it to hit 62mph in 5.7sec and a 152mph top speed. It will also return a claimed 32.1mpg and emit 204g/km of CO2.

Both gearboxes offer a standard stop-start function and operate in combination with a brake energy recuperation system. Further efficiency savings are made through a new electric power steering system.

Further X3 models are planned for the UK, including a 254bhp 3.0-litre xDrive28i petrol and a 201bhp xDrive23d that has a twin-turbocharged, four-cylinder diesel. But they are unlikely to go on sale until at least this time next year.

As with today’s X3, the new model will be available exclusively with four-wheel drive. No rear-wheel-drive version is planned for the UK, although BMW is still considering introducing such a model in North America.

Chassis developments for the new off-roader include new double wishbone front suspension and variable damping that incorporates BMW’s Dynamic Control system, which also influences the throttle, engine, steering and dynamic stability control mapping.

Production of the new X3 will take place at BMW’s Spartanburg facility in North America alongside the X5 and X6. By contrast, the first-generation X3 was produced at Magna in Graz, Austria — the same factory BMW has tapped to turn out the new Mini Countryman.

Greg Kable

See all the latest BMW X3 reviews, news and video