Lately, I've been running my car in Sport mode and it goes into sixth gear at about 55 mph or so. I thought this was a bit strange since my S-Type wouldn't go into sixth gear in Sport mode. Not a problem for me, but when I mentioned it to a salesman at the Jag dealer I frequent, he said it should stay in fifth gear. He thought some wires got crossed up somewhere in my transmission. For me, the car is working fine so I'll just continue to keep it as is.

 

Were you using the Cruise Control ? It will, correctly, go into 6th at the appropriate speed if you engage the CC even if you have selected Sport mode.

The transmission actually has more than 'normal' and 'sport' modes, it also has 'cruise' and 'hot' modes (the latter being a protection against overheating the transmission).

Salesmen at Jaguar ... are not always on top of things technical [British ironic understatement ! ]

 

Based on my understanding and personal experience with my XJ, sport mode just has the transmission shift a bit earlier or sooner than non-sport mode when you get on the gas a bit harder. It does not lock out any gear, and if you are being light on the foot, you shouldn't see any difference in the shifting or gears.

 

According to one the numerous training guides and introductions sport mode should lock out 6th (unless you engage the cruise control). It certainly works like that on mine.

 

I just ran it in traffic in Sport mode and did not use CC. The tranny shifted into 6th gear at the previously mentioned 55 mph. I wonder if it's something related to the adaptive feature of the transmission. Maybe a hidden feature

 

I checked this out on the motorway last night. At 70 mph, without the CC, it immediately changed down to 5th when I engaged sport mode, and went back up to 6th when I disengaged it. I then tried running at as steady a speed as I could, around 70, with sport engaged but without using CC and it remained in 5th all the time.

One oddity, I found that, at around 70mph with CC engaged, pressing the sport button to engage sport mode caused the transmission to change down to 5th, and then about one second later change back into 6th. (Pressing the sport button to disengage sport mode had no effect).

 

In my XJR, sport mode winds the gears out longer. It also takes it a bit to drop in 6th. While in Sport mode at highway speeds, let off the gas and it should drop into 6th. I think every trans has it's own personality. Mine will act differently on different days depending on temp, my driving habits, etc.

 

Well it's cat isn't it ... and there's just no telling with cats.

More seriously, I didn't have it out of CC but in sport mode for more than say a quarter of a mile, maybe if I'd given it longer ...

One thing I didn't mention is that if it's in 6th in CC with sport mode selected it doesn't seem to drop into 5th if you very gently ease the thottle up and very gently override the CC.

But like you say every one's different ... which I guess isn't so surprising after all, as the transmission has an adaptation function.