See also:

Closing the windows and glass sunroof/panoramic glass sunroof
Driving with the glass sunroof/panoramic glass sunroof and windows open results in increased air resistance and raises fuel consumption. ...

INTERIOR
The X5's interior lives up to luxury standards; it's not flashy, but the quality materials used inside and the attention to detail tell you it's no ordinary vehicle. My test car had upgrades like ...

Check the tire inflation pressure regularly
Check and, if necessary, correct the tire inflation pressure, at least twice a month and before starting on a long trip. Low tire inflation pressure increases rolling resistance and thus raises ...