WHERE the B4 stands out from the rest of the Liberty range is in the engine department, as it is the sole recipient of a turbocharged powerplant. It is the first Liberty model in seven years to reap the performance benefits of forced induction and now shoulders the responsibility of maintaining Subaru's performance image, along with the Impreza WRX and STi models. On a more superficial level, the blue leather seat, steering wheel and door trim are pretty swish and separate the B4 from its more conservatively appointed Liberty brethren.