Based on data from 48 vehicles, 3,245 fuel-ups and 1,196,992 miles of driving, the 2020 GMC Sierra 2500 HD gets a combined Avg MPG of 14.26 with a 0.12 MPG margin of error.

Any Engine Type 6.6L V8 DIESEL (41) 6.6L V8 GAS (7) Any Body Style Extended Cab Pickup (1) Crew Cab Pickup (11) Any Submodel SLE (3) SLT (6) AT4 (14) Denali (25)

Below you can see a distribution of the fuel-ups with 29 outliers (0.89%) removed.

Following shows the average MPG of each of the 48 vehicles in the system.

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• No Greater Love

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Nov 2021 • 18 Fuel-ups

  Property of mattjames11

• 12.3 Avg MPG

• L5P

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Apr 2021 • 50 Fuel-ups

  Property of jwmontoya

• 14.2 Avg MPG

• ‘Nali

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Jul 2023 • 40 Fuel-ups

  Property of raulserrano

• 17.7 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Sep 2020 • 151 Fuel-ups

  Property of Xaositek

• 16.2 Avg MPG

• Duramax

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added May 2021 • 97 Fuel-ups

  Property of Silentfun65

• 14.5 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD SLE 6.6L V8 GAS Automatic 6 Speed
  Added May 2020 • 68 Fuel-ups

  Property of uncledot

• 13.3 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Jan 2021 • 117 Fuel-ups

  Property of DMaxTRR

• 15.9 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jan 2022 • 146 Fuel-ups

  Property of BPowAT4HD

• 16.5 Avg MPG

• Sierra

  2020 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Jan 2023 • 22 Fuel-ups

  Property of bradford29

• 17.3 Avg MPG

• FLWKS 2500HD AT4

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Jun 2020 • 104 Fuel-ups

  Property of hockeyvillian

• 14.5 Avg MPG

• BatMobile II

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2020 • 155 Fuel-ups

  Property of Rocinante1

• 16.0 Avg MPG

• Big Red II

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Aug 2020 • 150 Fuel-ups

  Property of TackleBox

• 13.6 Avg MPG

• My Sierra 2500 HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2023 • 24 Fuel-ups

  Property of aricb23

• 10.9 Avg MPG

• Red

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed
  Added Mar 2020 • 135 Fuel-ups

  Property of llljrmd

• 16.5 Avg MPG

• Blue Beast

  2020 GMC Sierra 2500 HD SLT 6.6L V8 GAS Automatic 6 Speed Extended Cab Pickup
  Added Sep 2020 • 46 Fuel-ups

  Property of JustinID

• 13.5 Avg MPG

• GMC AT4

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Nov 2021 • 38 Fuel-ups

  Property of gil_bradshaw

• 15.6 Avg MPG

• 2020 AT4 2500HD

  2020 GMC Sierra 2500 HD AT4 6.6L V8 DIESEL Automatic 10 Speed
  Added Apr 2022 • 21 Fuel-ups

  Property of rab986

• 16.8 Avg MPG

• Sierra 2500HD Duramax

  2020 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Aug 2020 • 61 Fuel-ups

  Property of RamMan88

• 16.0 Avg MPG

• Denali 2500HD

  2020 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 10 Speed Crew Cab Pickup
  Added Nov 2020 • 29 Fuel-ups

  Property of eastcoasthd

• 14.2 Avg MPG

• FURY

  2020 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 10 Speed
  Added Sep 2020 • 28 Fuel-ups

  Property of Thumpy

• 14.3 Avg MPG

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