Why is there even the option for turning it off? Does it make a noticable difference in performance?
--
Costas Kotinopoulos 1997 850 GLT TURBO

On my 98 S70 T5M it induces "axle hop" on fast starts as the brakes
are applied and released. Does so in a rather violent manner, too
(to the extent that you back off the gas). In this case, it is
better to turn it off and let the tires spin a bit.

i leave mine off all the time on my 95 855 turbo. didn't find it too useful...maybe on rain and light snow it's best. on incline, 3rd gear start, snow tires (no chains), didn't help, tracs went off like crazy but i still slipped backwards.

Conversely, in extremely slippery conditions (ie: ice/snow) there may very well be a time when it is impossible to move without spinning the drivewheels, and TRACS not only prevents wheel slippage, but actually prevents the car from moving. I have heard of this from at least one close friend who rented a V70 AWD and had to be pushed out of a parking spot because TRACS prevented the car from moving.

Kojack,
I see your point and later models I understand default to "on" when started unlike my early 850 ('94) which is "off" untill turned on. One thought is when fast acceleration is needed (or wanted) from a dead start on say dry pavement, you don't want the Tracs prohibiting the likely wheel spin encountered when the pedal is put to the floor. 850R owners and T5 owners know what I'm talking about...