Cathydsrna

Excuse me if this question has already been asked but I am new here and just learning how to navigate the forums. I just purchased a 2022 RX450H and I am certain the salesperson told me I could use 87 octane gasoline (and I have seen this on-line as well) but the owners manual states that octane 91 should be used. What do you other RXhybrid owners use?

BillUK

I'm in the UK and our octane ratings are slighty different here. That said, I use premium fuel. It'll run fine on regular, it's just that I find I get a little better mileage with the premium, so the cost balances out. I don't know if it's the same over there, but our premium fuel also has an additive package of cleaners etc.

Sid03SVT

91 octane is required (RM/2 for US) or 96 octane (RON across the pond)

Don't listen to your dealer/salesperson, most of them don't know anything about the vehicles they sell other than "engine go brrrrr".
Trust the manual, the Lexus website & that little sticker inside of your fuel door that say "requires premium fuel" or "premium fuel only".
Link to official Lexus website, where your model is shown to require 91.
Lexus Support: Which fuel grade by year & model

I typically only use 93 (IS350) because 91 is rarely available in my area (87, 89, 93 are the norm).