Based on data from 40 vehicles, 2,222 fuel-ups and 816,617 miles of driving, the 2020 GMC Sierra 2500 HD gets a combined Avg MPG of 14.26 with a 0.15 MPG margin of error.

Any Engine Type 6.6L V8 DIESEL (34) 6.6L V8 GAS (6) Any Body Style Extended Cab Pickup (1) Crew Cab Pickup (9) Any Submodel SLE (3) SLT (5) AT4 (12) Denali (20)

Below you can see a distribution of the fuel-ups with 22 outliers (0.98%) removed.

Following shows the average MPG of each of the 40 vehicles in the system.

• «
• 1
• 2
• »

• Duramax

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added May 2021 • 79 Fuel-ups

  Property of Silentfun65

• 14.4 Avg MPG

• Neil GMC 2500HD

  2020 GMC Sierra 2500 HD SLE 6.6L V8 GAS Automatic 6 Speed Crew Cab Pickup
  Added Nov 2020 • 167 Fuel-ups

  Property of neilalvares

• 13.3 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jan 2022 • 100 Fuel-ups

  Property of BPowAT4HD

• 16.5 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD SLE 6.6L V8 GAS Automatic 6 Speed
  Added Mar 2022 • 93 Fuel-ups

  Property of hoodsh

• 14.4 Avg MPG

• Big Red II

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Aug 2020 • 140 Fuel-ups

  Property of TackleBox

• 13.7 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2023 • 18 Fuel-ups

  Property of aricb23

• 10.7 Avg MPG

• 2020 Denali 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2020 • 92 Fuel-ups

  Property of maaiman

• 16.1 Avg MPG

• 2020 Sierra 2500 Duramax

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Dec 2019 • 199 Fuel-ups

  Property of mnoland2000

• 12.9 Avg MPG

• COVID Cruiser

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2020 • 164 Fuel-ups

  Property of jambiefsj

• 16.9 Avg MPG

• Granite AT4

  2020 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed Crew Cab Pickup
  Added Oct 2020 • 109 Fuel-ups

  Property of NHATC

• 11.2 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Jan 2020 • 77 Fuel-ups

  Property of zardoz5

• 14.9 Avg MPG

• Sierra

  2020 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Jan 2023 • 3 Fuel-ups

  Property of bradford29

• 24.6 Avg MPG

• Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2020 • 57 Fuel-ups

  Property of bto71

• 14.1 Avg MPG

• BatMobile II

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2020 • 139 Fuel-ups

  Property of Rocinante1

• 16.0 Avg MPG

• AT4

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jul 2022 • 43 Fuel-ups

  Property of Dziuky

• 17.3 Avg MPG

• L5P

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Apr 2021 • 42 Fuel-ups

  Property of jwmontoya

• 14.3 Avg MPG

• My Denali 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Dec 2022 • 3 Fuel-ups

  Property of fasdon

• 10.9 Avg MPG

• GMC AT4

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2022 • 43 Fuel-ups

  Property of furlofoder

• 13.1 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Aug 2022 • 31 Fuel-ups

  Property of jeepin13

• 14.4 Avg MPG

• Gallo Negro

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added May 2022 • 9 Fuel-ups

  Property of doakman1

• 10.8 Avg MPG

• «
• 1
• 2
• »