2011 Lexus IS 350 User Guide - Page 541

6-1. Specifications How to read oil container label: The ILSAC (International Lubricant Standardization and Approval Committee) Certification Mark is added to some oil containers to help you select the oil you should use. IS350C "Toyota Genuine Motor Oil" is used in your Lexus vehicle. Use Lexus approved "Toyota Genuine Motor Oil" or equivalent to satisfy the following grade and viscosity. Oil grade: ILSAC multigrade engine oil Recommended viscosity: SAE 5W-30 SAE 5W-30 is the best choice for good fuel economy and good starting in cold weather. If SAE 5W-30 is not available, SAE 10W-30 oil may be used. However, it should be replaced with SAE 5W-30 at the next oil change. 6 Vehicle specifications Outside temperature The 5W portion of the oil viscosity rating indicates a characteristic of the oil which allows cold startability. Oils with a lower value before the W allow for easier starting of the engine in cold weather. The 30 in 5W-30 indicates the oil viscosity when the oil is at its operating temperature. An oil with a higher viscosity may be better suited if the vehicle is operated at high speeds, or under extreme load conditions. 553