I'm not sure about the 8 spd transmission. But when I redlined the demo car IS350 AWD F sport) in S+ on my test drive, it did actually automatically up shift though.

 

Yeah, it's happened to me a few times now when in M mode that it's automatically shifted from 1st to 2nd. The pisser of it is, I hit the flappypaddle at the same time, so it also then quickly jumped to 3rd. Super annoying. I've also found that the engine tends to fall on its face and kind of run out of steam about 300-400rpm before getting to redline, which is also annoying (regardless of which gear I'm in).

 

someone PM dbs600 to this thread, he has Lexus customer service complaint department on speed dial. i am sure he will be more than happy to voice his concerns about this issue.
has to be a design flaw!

does anyone know if the transmission only upshifts on 1st gear but will hold the rest? of if this symptom is consistent with 6 speeds and not the 8 speed?
I'm sure it was designed that away for a reason.

 

From a stop going straight it will automatically shift up (1st to 2nd then 2nd to 3rd) in M with TC off and in S+ mode. I have not done 3rd to 4th due to the simple fact I would be exceeding speed limits of the highway... It does not hit the rev limiter at all. I have a 8 speed. I have even tried downshifting into 2nd at a crusing/rolling speed and then flooring it, it still upshifts automatically once it hits redline...

 

This!!!! I have done this countless times. I now just ignore the paddle pointless shifters all together.

 

Yeah, so just to test again, last night in S+, M shift mode, trac and stability turned off...down shifted to 3rd, stomped on it to redline, it shifted on its own into 4th

Moderately annoyed by this, as I was lead to believe this wouldn't happen in this car. Time to scour through the manual to see if there IS a setting that either I or the dealership can change to stop this from happening.

 

I was out for a spirited driving session the other night and had my car while in M, S+, and Trac off, automatically shift up to 2nd then get stuck bouncing off the rev limiter in 2nd. I was pulling the Up paddle (yes, the up paddle, the one on the right, because I know someone's going to say "Maybe you were pulling the wrong one, Morty!") to no avail. The car was completely unresponsive.

 

Interesting. My 2007 Honda Fit, when in manual mode, will hold the gear to redline and bounce off it all day long until I manually shift it.

 

Lexus is just weird, at times. The gearbox in the IS F bounces off the rev limiter while in manual mode. Interesting behavior from the 3IS, where they both share the 8 spd.