Tow/haul is most useful while pulling such a load
in rolling terrain, in stop-and-go traffic, or when
you need improved low-speed control, such
as when parking.
...
Driving with tow/haul activated without a heavy
load or with no trailer will cause reduced fuel
economy and unpleasant engine and transmission
driving characteristics, but will not cause
damage.
IMHO: Без прицепа - в пробке, на парковке и по грязи - подходит, а остальное - баловство.
(Tow/Haul Mode, 2007 Cadillac SRX Owner Manual, p. 333)