See also:

Fuel tank capacity
Gasoline engine Fuel tank capacity: approx. 21.6 US gal/82 liters. Refuel promptly Refuel below a range of 30 miles/50 km; otherwise, engine functions are not ensured and damage may occur. ...

Compact Design
Just as BMW's compact 3 Series ranks below the midsize 5 Series, the five-seat X3 sits in the shadow of the larger X5. The styling clearly says BMW, but it's the multi-paneled look of earlier mode ...

On the front passenger seat
Deactivating airbags After installing a child restraint fixing system in the front passenger seat, make sure that the front, knee and side airbags on the front passenger side are deactivated. ...