Demanding driving

In demanding driving conditions, such as operating the vehicle in hot weather, towing a trailer, or driving for extended periods at higher altitudes than normal, it may be advisable to switch to higher octane fuel (91 or higher) or to change gasoline brands to fully utilize your engine's capacity, and for the smoothest possible operation.
NOTE
When switching to higher octane fuel or changing gasoline brands, it may be necessary to fill the tank more than once before a difference in engine operation is noticeable.
See also:
Operation
Controls and display
1 - Resume previous settings, increase speed (each additional press increases
speed by 2 - 1 mph (approximately 2 km/h). 3 - Standby mode on/off 4 - Set time
interval 5 ...
Tunnel console
1 Storage compartment (for CDs, etc.) under
armrest, AUX input/USB connector.
2 Includes cup holder for driver and passenger,
12-volt socket and small storage compartment. ...
Vehicle Overview
Volvo's smallest sedan, the compact S40, comes in 2.4i and T5 trim levels,
the latter offered in all- as well as front-wheel drive. A few years past a full
redesign, the S40 and its V50 wagon sist ...
