Volvo XC90: Specifications / Transmission fluid specifications
Under normal driving conditions, the transmission fluid will not need to be
changed during the transmission's service life. However, it may need to be changed
if the vehicle is driven frequently in adverse driving conditions.

Engine oil of type VCC RBS0-2AE 0W-20 must be used. Lower oil grades may not
offer the same fuel economy, engine performance or engine protection.
Volvo recommends:
General
See the Service and warranty booklet for information about oil change intervals...
The medium in the hydraulic brake system is called brake fluid and is used
to transfer pressure from e.g. a brake pedal via a master brake cylinder, which
in turn actuates the brake calipers...
Other information:
The steering wheel can be adjusted to various positions.
The steering wheel's reach and height can be adjusted.
WARNING
Adjust the steering wheel and ensure it locks into position before driving.
Never adjust the steering wheel while driving.
Steering wheel adjuster lever...
(Option/accessory.)
The function for assisting when driving downhill (HDC1) is a low-speed
function with increased engine braking. The function makes it possible to increase
or decrease the vehicle's speed on steep downhill gradients by only using the accelerator
pedal, without applying the brakes...