The 2001 GMC Sierra 1500 is available as a 2-door, 3-seat regular side. Starting at $16,690, the 2001 GMC Sierra 1500 SL 4x2 Regular Cab Short Box is powered by a 4.3L , 6 -cylinder engine that returns an EPA estimated 16-mpg in the city and 19-mpg on the highway. The top of the line 2001GMCSierra 1500SLT 4x4 Extended Cab Long Box , priced at $ 28,631 , is powered by a 4.8L , 8 - cylinder engine that returns an EPA estimated 15-mpg in the city and 18-mpg on the highway.