First off I did search for this issue already and found this thread that somewhat described what occurs in my 2IS but doesn't address it all the way. Shifting Issues

While mine holds on to 5th gear for a lot longer than I feel like it should, I included a video of how it holds onto 5th gear but the other area of concern is that when it finally upshifts to 6th the RPM's drop and then spike and then drop again. The only way I can think of describing this better is when riding a motorcycle and pulling the clutch in while riding and then popping the clutch and making the bike's rpms jump. Once the transmission/computer allows 6th gear to be engaged, for the next few miles the transmission feels as if it doesn't know what gear it should be in and is evident due to the rpms jumping all over once i get over 50+mph and let off the gas. When I let off the gas the rpms will drop from wherever i was cruising at to 700 back up to 1500 then back to 7-800.

 

That looks completely normal. Once the ambient temperatures near freezing, the car won't shift into 6th gear until it warms up. It's an emissions feature to get the catalytic converters to light off more quickly. I believe it's even mentioned in the owners manual.

You don't show the other problem in the video, so I'm not sure what you are talking about.

 

I bought my 2012 IS250AWD few months away when in summer, this is the first winter with it, so far i'm in same boat as you, indeed this car takes FOREVER to warm up. btw, the RPM of my car just like yours. jumping all over the places once released gas paddle

 

yea, trans takes a while for fluid to warm up, if you think of it the fluid is like honey when its that cold so it really needs to warm up before it will shift right.

 

Just like Jkenn6 said. Transmission fluid needs to warm up to shift properly. If you ever driven a really high performance manual car you will notice the shifting is much better when the transmission fluid has warmed up and can be very notchy when it is cold.

 

Completely normal when "COLD".

 

Yeah I drove my IS250 for 2 winters now. I've noticed whenever tempurature drops below freezing and when the engine is not warm yet, the RPM will dip significantly when you let go of the gas as if it was changing gears... but its not. Does not happen in the summer months.