Deposit control gasoline (detergent additives)

Volvo recommends the use of detergent gasoline to control engine deposits. Detergent gasoline is effective in keeping injectors and intake valves clean. Consistent use of deposit control gasolines will help ensure good drivability and fuel economy. If you are not sure whether the gasoline contains deposit control additives, check with the service station operator.
NOTE
Volvo does not recommend the use of external fuel injector cleaning systems.
See also:
Connecting external devices
Sockets for auxiliary devices in the storage compartment between
the front seats
An auxiliary device, such as an iPod or MP3 player can be connected to the audio
system via one of the sockets i ...
Comfort and convenience
While the interior of the Volvo S40 places an emphasis on style, form has not
been allowed to take precedence over function. The fascia ergonomics have been
carefully designed and drivers will fin ...
Folding down the rear seat backrests
The rear seat backrests can be folded down for additional loading space, see
page 92. ...
