Based on data from 60 vehicles, 4,734 fuel-ups and 1,790,289 miles of driving, the 2018 GMC Sierra 2500 HD gets a combined Avg MPG of 14.53 with a 0.11 MPG margin of error.

Any Engine Type 6.0L V8 FLEX (7) 6.6L V8 DIESEL (53) Any Body Style Extended Cab Pickup (2) Crew Cab Pickup (15) Any Submodel Base (2) SLE (3) SLT (22) Denali (33)

Below you can see a distribution of the fuel-ups with 85 outliers (1.76%) removed.

Following shows the average MPG of each of the 60 vehicles in the system.

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• Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Oct 2020 • 38 Fuel-ups

  Property of beamsf15e

• 14.5 Avg MPG

• Red Tank 15/40

  2018 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 6 Speed
  Added Feb 2018 • 39 Fuel-ups

  Property of jdelfin

• 15.0 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Feb 2021 • 168 Fuel-ups

  Property of long003

• 16.0 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Nov 2023 • 8 Fuel-ups

  Property of Whistle

• 15.0 Avg MPG

• Denali

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed Crew Cab Pickup
  Added Dec 2017 • 262 Fuel-ups

  Property of jlawles2

• 15.2 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Sep 2017 • 193 Fuel-ups

  Property of tstanley2128

• 15.9 Avg MPG

• 2018 Sierra Denali HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Jun 2018 • 233 Fuel-ups

  Property of xstaski

• 15.2 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 6 Speed
  Added Jun 2018 • 94 Fuel-ups

  Property of Boerklong

• 16.2 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Jan 2023 • 4 Fuel-ups

  Property of pcurran63

• 14.9 Avg MPG

• Ken’s

  2018 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 6 Speed
  Added Apr 2020 • 47 Fuel-ups

  Property of Cave0369

• 16.6 Avg MPG

• Denali HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed Crew Cab Pickup
  Added Sep 2022 • 5 Fuel-ups

  Property of EasyRhino

• 18.0 Avg MPG

• GMC Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Feb 2021 • 25 Fuel-ups

  Property of Krixus

• 12.7 Avg MPG

• 2018 Duramax

  2018 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 6 Speed Crew Cab Pickup
  Added Dec 2018 • 45 Fuel-ups

  Property of brbrb

• 15.5 Avg MPG

• Ghost

  2018 GMC Sierra 2500 HD SLE 6.6L V8 DIESEL Automatic 6 Speed Crew Cab Pickup
  Added Apr 2018 • 221 Fuel-ups

  Property of cowdoc

• 18.8 Avg MPG

• 2018 GMC Sierra Denali HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Dec 2017 • 63 Fuel-ups

  Property of Screagle

• 17.0 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD SLT 6.6L V8 DIESEL Automatic 6 Speed
  Added May 2020 • 50 Fuel-ups

  Property of tishma09

• 10.3 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Sep 2018 • 13 Fuel-ups

  Property of Jdcompman

• 15.4 Avg MPG

• 2018 Sierra Denali HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Jan 2018 • 120 Fuel-ups

  Property of LynnE24

• 15.0 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Feb 2020 • 72 Fuel-ups

  Property of yelruc2

• 13.2 Avg MPG

• My Sierra 2500 HD

  2018 GMC Sierra 2500 HD Denali 6.6L V8 DIESEL Automatic 6 Speed
  Added Jun 2020 • 5 Fuel-ups

  Property of Madodds

• 15.2 Avg MPG

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