What's the 2014 lexus gs 350 oil type?

The 2014 Lexus GS350 requires the use of SAE 5W-30 full synthetic oil. In emergency situations, You may be able to use SAE 5W-40 conventional for a short period of time. However, this isn't really recommended because of its inferior viscosity and its inclination to break down much more quickly. To understand why, You've got to look at oil weight. What the numbers mean is viscosity at startup temperature (5) and operating temperature (30 or 40). Lower numbers are better, so You're going to want to pay the extra few dollars for 5W-30. This will keep Your engine running more efficiently, which will allow it to serve You for a longer lifespan. You may even notice a few extra miles between fill ups in the process.