On my X5 once I experience knocking with using regular too... , but so far I did 300 miles with regular and no problem . I can't see the different's between my regular tank and fuel from the dealer , so far I have 520 miles on'it
Premium is $5 extra at fill up. Why even mess around, feed the beast what she wants!
I have lived by those words!
2006 LS430 Blue Onyx Pearl and Cashmere leather interior, Modern Luxury package with Sirius Satellite radio, Smart Access, and Sport Tuned Suspension Package with Chrome 18's.
2014 GX460 Starfire Pearl with Sepia, Driver Support Package, Rear Entertainment System, Trailer Hitch, and Preferred Accessory Package.
I would not short-change such a nice vehicle. An analogy would be to have a 5-star meal accompanied by a $10 bottle of wine. Just give it the recommended fuel, drive and enjoy the vehicle instead of worrying over saving some money when you have already bought a "luxury" ride.
There was issue with 2007-2010 Toyota FJ Cruisers in which Toyota initially recommended premium fuel for the vehicle. Members of the FJ forum began hassling Toyota about the reason for this since the Tacomas and 4Runners used the same engine but used regular fuel. Toyota eventually sent out an e-mail stating that FJ Cruisers for those model years would have no issues using regular fuel.
That being said, I have always used premium fuel in my 2007 FJ Cruiser. There are members of the FJ forums that use regular fuel, but noted a decrease in engine performance and power loss. It's not significant since some FJ owners can live with that, but it is noticeable. I'd rather use my engine's full potential.