Use 91 octane or higher octane rating premium gas for the 2009 Lexus RX350
93 octane, one of the top tiers if available
Part if the door handle pops off. Look under the dirt Handel and you should see it. Then use the key from the remote.
E85
Use exactly what is recommended by Lexus as listed in your owners manual.
I'm the owner of Auto Science in Dallas Texas. The owners manual and sticker on the gas filler says premium gas. So defiantly don't use 87 octane. Use 91 or up. It will get better gas mileage and prevent detonation that can cause damage to the engine.
The 2012 Lexus IS-F runs on premium unleaded (required).
The 2008 Lexus IS-350 runs on premium unleaded (required).
The 2009 Lexus IS-350 runs on premium unleaded (required).
The 2011 Lexus IS-350 runs on premium unleaded (required).
The 2006 Lexus IS-350 runs on premium unleaded (required).
The 2012 Lexus LFA runs on premium unleaded (required).