Based on data from 66 vehicles, 3,845 fuel-ups and 1,236,484 miles of driving, the 2021 GMC Sierra 2500 HD gets a combined Avg MPG of 13.15 with a 0.12 MPG margin of error.

Any Engine Type 6.6L V8 DIESEL (48) 6.6L V8 GAS (17) Any Body Style Extended Cab Pickup (1) Crew Cab Pickup (15) Any Submodel Base (2) SLE (6) SLT (9) AT4 (21) Denali (28)

Below you can see a distribution of the fuel-ups with 19 outliers (0.49%) removed.

Following shows the average MPG of each of the 66 vehicles in the system.

• «
• 1
• 2
• 3
• 4
• »

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2024 • 7 Fuel-ups

  Property of crossfamily

• 16.5 Avg MPG

• 2021 Sierra 2500HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Jan 2024 • 40 Fuel-ups

  Property of Bost05

• 12.4 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 DIESEL Automatic 10 Speed
  Added Jan 2023 • 93 Fuel-ups

  Property of Croybal06

• 13.6 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLT 6.6L V8 GAS Automatic 6 Speed
  Added Jan 2021 • 35 Fuel-ups

  Property of NGreen08

• 10.4 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed
  Added May 2021 • 216 Fuel-ups

  Property of Buellx72

• 11.3 Avg MPG

• 2021

  2021 GMC Sierra 2500 HD Denali Crew Cab Pickup
  Added Dec 2020 • 179 Fuel-ups

  Property of lampmant

• 12.9 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Apr 2023 • 63 Fuel-ups

  Property of bcfiremedic

• 12.5 Avg MPG

• DENALI 2021

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Dec 2020 • 105 Fuel-ups

  Property of rivcoinc

• 14.6 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 DIESEL Automatic 6 Speed
  Added Apr 2023 • 204 Fuel-ups

  Property of mcgr0401

• 12.8 Avg MPG

• 2500Hd GMC

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added May 2021 • 134 Fuel-ups

  Property of jmgolden1978

• 13.8 Avg MPG

• 2021 GMC Sierra 2500 HD

  2021 GMC Sierra 2500 HD 6.6L V8 GAS Automatic 6 Speed
  Added Mar 2021 • 65 Fuel-ups

  Property of Hay_Man_40

• 11.2 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Sep 2023 • 143 Fuel-ups

  Property of SeB21

• 17.1 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLT 6.6L V8 GAS Automatic 6 Speed
  Added Jan 2021 • 211 Fuel-ups

  Property of kbeazley

• 10.7 Avg MPG

• BigTruck

  2021 GMC Sierra 2500 HD 6.6L V8 GAS Automatic 6 Speed Crew Cab Pickup
  Added Mar 2023 • 56 Fuel-ups

  Property of pmhanson

• 12.7 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed
  Added Jun 2021 • 166 Fuel-ups

  Property of gregnola

• 12.4 Avg MPG

• 2021 Sierra Denali HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Dec 2020 • 171 Fuel-ups

  Property of LynnE24

• 14.3 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Dec 2022 • 42 Fuel-ups

  Property of ryanhnicholson

• 11.6 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 GAS Automatic 10 Speed
  Added Oct 2021 • 140 Fuel-ups

  Property of bdamats

• 11.2 Avg MPG

• GMC Sierra 2500 AT4

  2021 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed
  Added Mar 2022 • 86 Fuel-ups

  Property of 22GMCAT4HD

• 12.4 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Jul 2024 • 3 Fuel-ups

  Property of josterhout1

• 16.1 Avg MPG

• «
• 1
• 2
• 3
• 4
• »