See also:

Setting a speed
Use the or buttons set the vehicle's current speed. The set speed is shown in the display. NOTE Cruise control cannot be engaged at speeds below 20 mph (30 km/h). ...

Use of Additives
With the exception of gas line antifreeze during winter months, do not add solvents, thickeners, or other store-bought additives to your vehicle's fuel, cooling, or lubricating systems. Overuse ...

Engine oil
Engine oil must meet the minimum ILSAC specification GF-4, API SL, or ACEA A1/B1. Lower quality oils may not offer the same fuel economy, engine performance, or engine protection. Volvo recommen ...