jrobe

This is complete bs. There is no more energy in a gallon of regular vs premium fuel. This has been tested to death by Consumer Reports and many other non-biased testing labs. A single person's first hand test results is completely meaningless with far too many variables that can alter the results. There are certainly other reasons to use premium fuel and it makes perfect sense to use the fuel type recommended by Lexus but fuel economy is not one of them.

bamalam

I agree. I did a ~6,000+ mile test of 87 and 93 octane fuels and noted a 2.6% mileage increase when using 93. That small improvement was not nearly enough to make up for the 20% increase in fuel cost. I noted no material difference in driving characteristics between the fuels, either. My testing is documented here: 4RX Mileage Thread - Page 23 - ClubLexus - Lexus Forum Discussion.

Freds430

Absolutely true. Watch the YouTube clip from the CBC on gasoline grades. They confirm zero difference in mpg or performance. Tom and Ray Magliozzi Car Talk said the exact same thing.