2011 Cadillac DTS Owner's Manual - Page 320

Viscosity Grade SAE 5W-30 is the best viscosity grade for the vehicle. Do not use other viscosity oils such as SAE 10W‐30, 10W‐40, or 20W-50. always select an oil that meets the required specification, dexos. See "Specification" earlier in this section for more information. Engine Oil Additives/Engine Oil Flushes Do not add anything to the oil. The recommended oils with the dexos specification and displaying the dexos certification mark are all that is needed for good performance and engine protection. Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty. What to Do with Used Oil Used engine oil contains certain elements that can be unhealthy for your skin and could even cause cancer. Do not let used oil stay on your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly dispose of clothing or rags containing used engine oil. See the manufacturer's warnings about the use and disposal of oil products. Cold Temperature Operation: In an area of extreme cold, where the temperature falls below −29°C (−20°F), an SAE 0W-30 oil should be used. An oil of this viscosity grade will provide easier cold starting for the engine at extremely low temperatures. When selecting an oil of the appropriate viscosity grade, be sure to 6-18 Used oil can be a threat to the environment. If you change your own oil, be sure to drain all the oil from the filter before disposal. Never dispose of oil by putting it in the trash or pouring it on the ground, into sewers, or into streams or bodies of water. Recycle it by taking it to a place that collects used oil.