Does a Lexus Rx 450h 2015 really need premium gas as recommended by Lexus
Yes, per your owners manual page 810: “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance.” Required not recommended
If the manufacturer SAYS it requires premium, than you should. If it says premium is recommended, its your choice. But as @pyrolord314 says, your car requires premium.