Sierra 2500HD SLT, 4D Crew Cab, Vortec 6.0L V8 SFI Flex Fuel VVT, 6-Speed Automatic HD Electronic with Overdrive, 4WD, Onyx Black, Black Leather. Onyx Black 2018 GMC Sierra 2500HD SLT 4WD 6-Speed Automatic HD Electronic with Overdrive Vortec 6.0L V8 SFI Flex Fuel VVT Recent Arrival! Team hyundai of bend dlr 4250 .