I disagree, because I have seen it happen. Maybe not Lexus "corporate" but Lexus "salespeople" will tell customers that they can use regular unleaded to make the sale. Most people buying cars don't frequent these types of forums so they are not privy to these types of conversations. Many consumers don't go into the physics of octane rating, they just know that if the book says you got to use premium and premium gas is 20¢ to 40¢ more expensive per gallon, then they may tend towards a high end vehicle that does not "recommend" premium. Now, if the salesman says, "you can use regular if you have to, the engine will compensate" then the sale is most always made.
As for "Lexus recommended brand oil"..........DO NOT GET ME STARTED ON THIS TOPIC AS IT IS A BEATEN HORSE. use the search function and look for a member named "monarch". DON"T GO THERE!!!!
Tranny fluid is a different story, I agree there, use Toyota T-IV or WS if it calls for it.
steviej
As for premium or regular, we have found that using a higher grade gas gives you better gas mileage, which in the long run makes it more economical. We have tried this "experiment" on each car we've owned and it does make a difference, even on an average run of the mill make and model. But, don't take my word for it.....try it yourself.