Must I Fuel my new IS250AWD with premium Fuel? If so what Octane ? Also what should I expect for Maintainence schedule?
Getting my IS250AWD Smokey Graphite/Sterling Int. in 1month. Exxxxxxxxxcccccccciiiitttteeedd !!

 

Welcome to CL! All New IS models require Premium Unleaded. You can use lower octanes for temporary usage but it's best to use premium as the 2GR-FSE 3.5L and 4GR-FSE 2.5L V6's are both high compression engines. Off the top of my head 11.8:1 and 12.0:1 respectively.

 

Definitely use the the premium fuel in your lex. In your owners portfolio there is a small booklet called the "Owner's Manual Supplement" that has your maintenance schedule at the back of it. Your 5000 mile service is free and the book has a 5000 mile interval schedule with a brief description of what is to be done/inspected at each service. You can always do your oil changes more frequent, but the book shows every 5k.