The ( my 2003 X308 XJR) owners manual does not really clarify just what "sports mode" is really all about. What I could gather is that it changes the steering and suspension characteristics and offers a means to force the magnificent MERC 5 speed tranny into a "manual" shifting mode ( including a ridiculously high torque 1st gear) which would be suitable for going up the side of a building.

My question to the forum is that how does a guy that doesn't routinely drive in the Le Mans or Indy 500 properly utilize the "sport option" on this closet monster ? .Is there an instruction manual on this ? Techniques , etc ?

I've only tried it once on a deserted back road. I pressed the "sport " switch at a standtill then hammered the accelerator . When the car's rear wheels began to spin and burn $500 rear tires , I immediately "shut it down"

I was astonished. that a big cat saloon of this weight could do that.....wow ! Any info on Sport mode feedback ...much appreciated

 

What you've gathered is all completely wrong.

All that the sport button does is alter the shift points of the transmission to give a sportier drive. The mode is "utilized" by pressing the button and then driving the car.

This is exactly what the manual says. I just read mine and I don't see how it is vague.

Manual shifting mode is available whether or not the box is in sport mode.

It has no effect on steering or suspension.

Did you know that you could use sport mode, and then be sparing with the accelerator so that the wheels don't spin?

 

Mine is always in sport mode. It doesn't feel any different unless you mash the accelerator. Then again, I have a VDP. ;^)

 

All the sport mode does on the ZF transmission is to raise the shift points about 300 rpm's. That makes it feel a little sportier in that you drive a little higher up in the HP band.

I would leave mine in sport all the time except that unless you get above 55 mph it will never shift into top gear and costing maybe 1+ mpg in fuel mileage.

 

And start in first gear otherwise the XJR start in second. And BTW, for the wheels to spin TC need to be off

 

Yep, all it does in enable first gear for launches, raises the shift points ~350 rpm, firms up the shifts, and makes it hold gear longer on hard acceleration. Mercedes has always used a strange gearing strategy where they make the final drive ratio in the differential very tall and then to compensate they make the transmission gears very short. This does make the transmission naturally stronger, which is why they do it I suppose. So since they're using the Merc transmission, they had to copy this strategy, which is why the final drive ratio is so much taller in the X308 than it was in the X300, which used GM sourced transmissions with a more "standard" gearing strategy. But this all means that first gear is VERY low in the Merc transmission, and gives a ton of torque multiplication, leading to hard acceleration and a quick shift into second, which is not smooth, so they make it start in second for a nice long smooth launch. Until you want beastly acceleration, which the sport button enables.

 

The XKR sport mode also stiffens the adaptive shocks. Don't the XJR's have them?