I wish we did have some selectability of the CATS. But both functions could have easily been engaged via single switch for the cars that do have CATS. But a four position soft-reg-sport-track selection switch sould be my choice. Oh well ... a 2011 XFR I guess.

My S-type 3.0, obviously not an STR, will delay shifting into 6th until roughly 80 MPH when "S" mode is engaged on the transmission (which for me is all the time...).

As I understood it, you still get 6th gear but the torque converter doesn't lock. It keeps the coupling fluid. Shift points are obviously altered to make the upper rpm range available. We all know what a beautiful place that rpm range is.

I reckon it will lock. Did you read a Jaguar document that says otherwise?

Very vague recollection on my part. I had been getting deep into research of the ZF material prior to doing my fluid and filter service, but that was some time ago. I recalled some mention of the S switch holding out lockup for the top gear along with the shift point profile change. Almost to sound that if you had fifth engaged on the shifter, it would become the top gear only allowing for lockup in the lesser gears, but that possibility was only wondered by me, not read. The ZF was pioneering in its day particularly in how it modulated it's lockup in all gears. Was it Jaguar documentation? Maybe not, it may have been ZF. Perhaps it does lock but just differently as does the shifts. In the end, it doesn't matter to me, I just love the transmission. So smooth. I can honestly say that I love literally everything about this car. My favorite by far, and I've had a lot of cool rides.

The jag doc make a point of saying it locks in all forward gears. Makes sense that it would, whether in S or not.

In 3.4 and 3.4.1 lines can be drawn that among other inputs, the mode switch contributes to alteration of shifts and lock up to match current style while reserving the ability to return normal lockup when enthusiasm return to normal. It also says somewhere in there that the lockup pressure is always in play just modulating to some variable output. Either way, it shows a sophistication in operation that goes beyond more simple decision trees within the controller. Certainly can appreciate what it does for me.

I don't get why it would want to not be locked. To change speed the car can just change revs. What sense can it make to not be locked up?

Bear in mind the PCM & TCM exchange messages via CAN all the time.

I can see how it makes sense. The torque converter locks as to save MPG through lowering revs and removing slip, it also lowers heat which in the simplest sense, heat = wasted energy not put to work. When unlocked, the torque converter brings benefit as a torque multiplier. It is why it has to wait until it has a cruising type load as to allow lockup in the first place. Once again, it is the control intelligence being applied to modulate the lockup to in effect, ride a curve more precise than most other cars and involving more forms of input. Particularly impressive considering the era being discussed. It isn't horsepower making sport mode so satisfying, it is the throttle responsiveness that I have appreciation for.

I'd say it can get responsiveness from engine revs without messing with the lock up.

If anyone wants to monitor the CAN packets it's a way to be sure...