Volvo 2008 S40 Owner's Manual page 228

Engine oil
American Petroleum Institute (API) symbol
The API Service Symbol "donut" is divided into three parts:
The upper section describes the oil's performance level.
The center identifies the oil's viscosity.
The lower section indicates whether the oil has demonstrated energy-conserving properties in a standard test in
comparison to a reference oil.
1
See the information on page
255
11 Specifications
Engine specifications
1
The engine specifications for horsepower and torque listed in this table are based on the use of premium fuel.
Charge air cooler (Intercooler)
Turbocharged engines employ a turbo-compressor to force air into the engine inlet manifold and a charge air cooler to
cool the compressed inlet air. The resulting increase in air flow raises pressure in the intake manifold and increases
254.