GMC averages 18.5 mpg combined across 15 petrol and diesel models (1984–2027). The best on record does 32 mpg, the thirstiest 13 — a yearly fuel gap of about $1,754. Its 3 electric models sit apart at 57.3 MPGe — 58.8 kWh per 100 miles, about $1,200 a year to charge, which is $876 less than the average GMC costs to fuel.
What that actually costs
What a GMC costs to feed, at 12,000 miles a year and $3.20 a gallon.
| Measure | Value |
|---|---|
| Average combined | 18.5 mpg |
| Fuel per year | $2,076 |
| Most frugal on record | 32 mpg — $1,200 a year |
| Thirstiest on record | 13 mpg — $2,954 a year |
| Its electric models | 57.3 MPGe — $1,200 a year to charge |
GMC models by gas mileage
From the most frugal down. The yearly figure is what the fuel actually costs at 12,000 miles.
| Model | Average mpg | Best / Worst engine | Fuel per year |
|---|---|---|---|
| GMC Terrain | 32 / 16 | $1,648 | |
| GMC Acadia | 25 / 18 | $1,803 | |
| GMC Canyon | 25 / 16 | $1,892 | |
| GMC Sonoma | 23 / 15 | $1,910 | |
| GMC Sierra | 26 / 15 | $2,053 | |
| GMC Jimmy | 23 / 14 | $2,133 | |
| GMC Safari | 22 / 16 | $2,133 | |
| GMC AT | 19 / 17 | $2,145 | |
| GMC Caballero | 21 / 16 | $2,157 | |
| GMC Yukon | 23 / 13 | $2,157 | |
| GMC Yukon XL | 23 / 14 | $2,182 | |
| GMC Vandura | 20 / 15 | $2,233 | |
| GMC Envoy | 17 / 15 | $2,370 | |
| GMC Suburban | 18 / 13 | $2,510 | |
| GMC Savana | 17 / 13 | $2,526 |
The electric GMCs, measured differently
GMC has 3 models that never visit a filling station, averaging 57.3 MPGe. That figure looks four times better than the 18.5 mpg the petrol GMCs manage, but the two are not the same unit — so we keep them apart and price the electric ones in kilowatt-hours.
| Model | MPGe | kWh / 100 mi | Charging per year |
|---|---|---|---|
| GMC Sierra | 51.1 | $1,042 | |
| GMC Hummer EV Pickup | 63.6 | $1,297 | |
| GMC Hummer EV SUV | 63.6 | $1,297 |
MPG is a number. Dollars per year is the answer.
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How we count
GMC rests on 492 EPA ratings covering 15 models from 1984 to 2027, plus 3 electric ones counted separately in MPGe. The laboratory numbers are EPA's and go in unchanged; the money is ours, at 12,000 miles a year and $3.20 a gallon. Full method.
Frequently asked questions
What is the average GMC gas mileage?
18.5 mpg combined across 15 models and 492 EPA ratings, from 1984 to 2027 — 43 model years in one figure, which is why it sits below what a new GMC does today.
Which GMC model is the most economical?
The GMC Terrain at 23.3 mpg, about $1,648 a year in fuel, against the Savana at 15.2 mpg and $2,526 — a gap of $878 a year between the two ends of the same badge.
How much does a GMC cost to run?
About $2,076 a year in fuel, at 12,000 miles and $3.20 a gallon. Over five years that is $10,380, before a single service.
Does GMC make anything electric?
Yes — 3 models, rated 57.3 MPGe rather than in mpg, which works out to 58.8 kWh per 100 miles and roughly $1,200 a year at the socket. That is $876 less than the average petrol GMC, though the two ratings are not in the same unit.
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