2008 Volvo S60 Owner's Manual - Page 172

Oil additives must not be used. NOTE Synthetic oil is not used when the oil is changed at the normal maintenance services. This oil is only used at customer request, at additional charge. Please consult a trained and qualified Volvo service technician. Oil viscosity (stable ambient temperatures) Operation in hot climates When temperatures exceed 104° F (40° C) in your area, Volvo recommends, for the protection of your engine, that you use a heavier weight oil, such as such as SAE 5W-40 or 0W-40. See the viscosity chart. Operation in temperate climates Incorrect viscosity oil can shorten engine life. Under normal use when temperatures do not exceed 104° F (40° C), SAE 5W-30 will provide good fuel economy and engine protection. See the viscosity chart. Extreme engine operation Synthetic oils meeting SAE 0W-30 or 0W-40 and complying with oil quality requirements are recommended for driving in areas of sustained temperature extremes (hot or cold), when towing a trailer over long distances, and for prolonged driving in mountainous areas. 193 09 Maintenance and servicing Engine oil American Petroleum Institute (API) symbol The API Service Symbol "donut" is divided into three parts: