What's the 2015 lexus rx 350 engine oil type?

Your 2015 Lexus RX350 uses 0W-20 synthetic motor oil from the factory, though You're free to use 5W-20 in a pinch. You can put 6.4 quarts of oil in, which includes a new filter (since that'll have space for oil as well). Don't put more than 30 feet per pound of torque on the oil drain plug when You tighten it back up. Price wise, You're looking at about $13 a quart for a good brand like Amsoil's Signature Series 0W-20, part number ASMQT-EA. If You have a conventional oil in here (not recommended) You'll want to change the oil every 3000 or so miles; if You go with the recommended synthetic, though, You can go between 7000 to 10,000 miles between oil changes.