I agree, they all seem to exhibit the same behavior. Even the ES350 suffers from this issue despite being a completely different engine layout etc. you are definitely correct that all these Lexus/Aisin transmissions act similarly. As for the differences in the transmissions between the F and the LS460, they are mechanically identical as far as I can tell, however, the LS460 application seems to be much lazier and just generally worse. I understand the need for a smooth transmission in a luxury car like that, but the F in normal mode offers about as smooth of a shifting experience as I have ever experienced in any luxury car and yet when you switch to sport or sport + the shifts become far more immediate. No idea why the LS460 and f sport models cannot be tuned this way. If it’s purely a matter of calibration, that is pretty disappointing as Lexus is leaving a lot of performance and enjoyment on the table. It’s a simple formula that makes sense. Smooth in normal mode, fast and aggressive shifts in sport modes. If anyone knows a mechanical reason for these differences please enlighten me as I am very interested. Having driven a 3rd gen IS350 f sport as a loaner (and generally enjoying it) I felt that the car was let down by the worse transmission tuning even in manual mode.

edit: the is350 was the rear wheel drive 8 speed

 

As an owner of both an IS 350 RWD and a 330i, I agree. That ZF trans is on another level compared to the one in the IS. But like you said, even having the quicker shifts from the F would make a big difference. Having said that, if I get on a back road and have fun with the Lexus I don't find myself worrying too much about the transmission.

 

Very true, that sweet V6 is very potent at the top of second gear.

 

this is all really insightful. thanks to all who chimed. i guess i'll just accept it as a quirk of the car. the oil level was corrected, but didn't make a difference. the spark plugs need to be replaced and i have an appointment this saturday just because it needs to be done, but i don't expect it to fix the problem.

it's just a bit annoying because this didn't happen with the 6-speed transmission in a previous IS that i had. i guess i'm just super used to the refined zf in the audi, but the audi is not going to my daily, it's going to be my SO's.