We use a Toyota Sienna minivan with 3.3 l, 230 hp engine, 5 speed auto
and front wheel drive to tow a Bayliner 175. The minivan is rated to
tow 3500 lb (standard, no optional equipment required), while the boat
weights approx. 2500 lb (with trailer and full tank of gas). We never
had any issues towing, launching or retriving the boat and we never
felt the need for 4 wheel drive or more power, even on steep and wet
ramps. Worst case, if the ramp was very uneven and the wheel of the
trailer got stuck against a bump or fallen into a hole, the front wheel
of the van have spun if I stepped to hard on the gas pedal, but I never
had a problem getting out of the situation just by using the gas pedal
gently and gradually increasing the traction without letting the wheel
to spin agan.