How could premium fix a bad engineered tranny???
Some comments on the topic: when I complained about my car hesitating when I come to a full stop and then immediately step on the gas, my Lexus service rep. said it could not be fixed, it had to do with the ECU settings in the transmission. I also complained about sooty tail pipes and he just said it was not important. Then at 20K miles, I went to another dealership with my 2006 GS300 AWD and complained about sooty pipes. The service rep at that Lexus dealership recommended I use regular instead of premium gas.
Net result is that my mileage improved, especially for highway travel, and after 5K miles the pipes appear to be loosing the black soot that was there prior. I never personally cleaned the pipes. Then lo and behold, a funny thing happened, I had forgotten about it until the subject of tranny hesitation was brought up again: My car no longer hesitates after I come to a full stop and want to get moving again.
Other than that I have only two beefs: (1) not enough power, unless I get aggressive with the gas pedal, in which case the transmission is often downshifting, and (2) The dipstick showed I had used almost a quart of oil atfter 5K, when I added a half pint, the dipstick read on the halfway mark; wish the dipstick were not as long and was more accurate.
Pleased as punch