Based on data from 57 vehicles, 2,432 fuel-ups and 768,010 miles of driving, the 2021 GMC Sierra 2500 HD gets a combined Avg MPG of 13.13 with a 0.15 MPG margin of error.

Any Engine Type 6.6L V8 DIESEL (38) 6.6L V8 GAS (17) Any Body Style Extended Cab Pickup (1) Crew Cab Pickup (11) Any Submodel Base (3) SLE (5) SLT (7) AT4 (18) Denali (24)

Below you can see a distribution of the fuel-ups with 9 outliers (0.37%) removed.

Following shows the average MPG of each of the 57 vehicles in the system.

• «
• 1
• 2
• 3
• »

• Big Bubba. My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2021 • 60 Fuel-ups

  Property of moose57

• 17.1 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 DIESEL Automatic 6 Speed
  Added Apr 2023 • 30 Fuel-ups

  Property of mcgr0401

• 11.0 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 GAS Automatic 10 Speed
  Added Oct 2021 • 91 Fuel-ups

  Property of bdamats

• 11.1 Avg MPG

• BigTruck

  2021 GMC Sierra 2500 HD 6.6L V8 GAS Automatic 6 Speed Crew Cab Pickup
  Added Mar 2023 • 27 Fuel-ups

  Property of pmhanson

• 14.6 Avg MPG

• 2021 Sierra Denali HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Feb 2021 • 99 Fuel-ups

  Property of ccc2511

• 16.0 Avg MPG

• 2021 2500HD Denali

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Apr 2021 • 109 Fuel-ups

  Property of DP68

• 17.1 Avg MPG

• 2021 Denali HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Nov 2020 • 65 Fuel-ups

  Property of DenaliDad

• 14.5 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed
  Added May 2021 • 142 Fuel-ups

  Property of Buellx72

• 11.5 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 GAS Automatic 6 Speed
  Added Nov 2021 • 75 Fuel-ups

  Property of Danm1228

• 11.5 Avg MPG

• DENALI 2021

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Dec 2020 • 72 Fuel-ups

  Property of rivcoinc

• 14.2 Avg MPG

• 2021 Sierra Denali HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Dec 2020 • 123 Fuel-ups

  Property of LynnE24

• 14.6 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLE 6.6L V8 DIESEL Automatic 10 Speed
  Added Jan 2023 • 34 Fuel-ups

  Property of Croybal06

• 14.2 Avg MPG

• AT4

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Oct 2022 • 40 Fuel-ups

  Property of scrabble890

• 15.2 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 GAS Automatic 6 Speed
  Added Jun 2021 • 116 Fuel-ups

  Property of gregnola

• 12.4 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD SLT 6.6L V8 GAS Automatic 6 Speed
  Added Jan 2021 • 26 Fuel-ups

  Property of NGreen08

• 10.9 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Dec 2022 • 22 Fuel-ups

  Property of ryanhnicholson

• 12.0 Avg MPG

• 2021

  2021 GMC Sierra 2500 HD Denali Crew Cab Pickup
  Added Dec 2020 • 118 Fuel-ups

  Property of lampmant

• 12.6 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Apr 2023 • 6 Fuel-ups

  Property of bcfiremedic

• 13.0 Avg MPG

• My Sierra 2500 HD

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2021 • 91 Fuel-ups

  Property of xETERNALx

• 13.5 Avg MPG

• Sierra 2500 HD aka Sully

  2021 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added May 2021 • 73 Fuel-ups

  Property of Ryot

• 12.2 Avg MPG

• «
• 1
• 2
• 3
• »