BMW X3 vs Mercedes-Benz GLC-Class: fuel economy and fuel cost

In model year 2026 the BMW X3 is the cheaper of the two to fuel: about $2,750 a year for its lowest-cost configuration (X3 xDrive30, 29 MPG combined), against $2,950 for the Mercedes-Benz GLC-Class (GLC300, 27 MPG combined). That is $200 a year, or $1,000 over five years.

A frequently cross-shopped pair of rivals. Costs assume 15,000 miles a year and the same fuel and electricity prices for both vehicles, using the EPA combined rating (55% city, 45% highway). Each figure is rounded to $10 and every difference is calculated from the rounded values.

The EPA is still publishing model year 2027 ratings, so this page compares model year 2026, the latest complete year.

Illustration: Small SUVs

Hybrid
Small SUVs

BMW X3

Lowest fuel cost configuration

X3 xDrive30

Combined

City

Highway

Annual fuel cost

$2,750

$18.33 per 100 miles

15,000 mi/yr, same fuel prices

2 configurations in MY2026

Illustration: Wagons

Hybrid
Wagons

Mercedes-Benz GLC-Class

Lowest fuel cost configuration

GLC300

Combined

City

Highway

Annual fuel cost

$2,950

$19.67 per 100 miles

15,000 mi/yr, same fuel prices

5 configurations in MY2026

What the fuel costs

Annual fuel cost of the lowest-cost configuration

BMW X3$2,750 a year · $18.33 per 100 mi
Mercedes-Benz GLC-Class$2,950 a year · $19.67 per 100 mi

Difference per year

$200

BMW X3 costs less to fuel

Over 5 years

$1,000

$200 a year × 5, 15,000 mi/yr, same fuel prices

Head to head, MY2026

BMW X3 and Mercedes-Benz GLC-Class compared on their lowest fuel cost configuration
Measure	BMW X3	Mercedes-Benz GLC-Class
Lowest-cost configuration	X3 xDrive30	GLC300
Powertrain	Hybrid	Hybrid
Combined rating	29 MPG (better)	27 MPG
City rating	27 MPG (better)	24 MPG
Highway rating	33 MPG (better)	32 MPG
Annual fuel cost	$2,750/yr (better)	$2,950/yr
Cost per 100 miles	$18.33 (better)	$19.67
Annual cost range, all configurations	$2,750–$2,940	$2,950–$3,730
Configurations in MY2026	2	5
EPA class	Small SUVs	Wagons

Best configuration by powertrain

Lowest-cost configuration of each powertrain, BMW X3 and Mercedes-Benz GLC-Class
Powertrain	BMW X3	Mercedes-Benz GLC-Class
Hybrid	29 MPG · $2,750/yr X3 xDrive30	27 MPG · $2,950/yr GLC300

Each cell shows the combined rating and the annual fuel cost of the lowest-cost configuration with that powertrain.

Where each one comes out ahead

Generated from the numbers above, comparing the lowest fuel cost configurations. No subjective judgements.

BMW X3

Lower annual fuel cost: $2,750 vs $2,950
Higher combined rating: 29 MPG vs 27 MPG
Higher city rating: 27 MPG vs 24 MPG
Higher highway rating: 33 MPG vs 32 MPG

Mercedes-Benz GLC-Class

Not ahead on any measure listed here.

Year by year

Combined rating and annual fuel cost by model year, BMW X3 and Mercedes-Benz GLC-Class
Model year	BMW X3		Mercedes-Benz GLC-Class
Model year	Combined	Per year	Combined	Per year
2026	27–29 MPG	$2,750–$2,940	22–27 MPG	$2,950–$3,730
2025	27–29 MPG	$2,750–$2,940	20–27 MPG	$1,850–$3,900
2024	17–25 MPG	$3,220–$4,750	21–29 MPG	$2,820–$3,900
2023	17–25 MPG	$3,220–$4,750	20–28 MPG	$2,880–$4,050
2022	17–25 MPG	$3,220–$4,750	19–24 MPG	$3,390–$4,250
2021	16–27 MPG	$2,610–$4,970	17–25 MPG	$3,250–$4,630
2020	16–27 MPG	$2,610–$4,970	18–25 MPG	$2,290–$4,420
2019	23–26 MPG	$3,110–$3,550	18–25 MPG	$2,650–$4,510
2018	23–25 MPG	$3,260–$3,520	18–25 MPG	$2,650–$4,510
2017	21–24 MPG	$3,400–$3,780	20–24 MPG	$3,310–$3,990
2016	21–30 MPG	$3,200–$3,750	24 MPG	$3,310–$3,400

Earlier model years are costed with today's fuel prices, so the table shows how each model's efficiency changed, not what fuel cost at the time. Ranges cover every configuration of that model year.

Frequently asked questions

Which is cheaper to fuel, the BMW X3 or the Mercedes-Benz GLC-Class?

The BMW X3 is cheaper: about $2,750 a year against $2,950 for the Mercedes-Benz GLC-Class, a difference of $200 a year. That compares the lowest-cost configuration of each in model year 2026 at 15,000 miles a year with the same fuel prices.

How much would the BMW X3 save over five years?

About $1,000 ($200 a year for five years), assuming 15,000 miles a year and the same fuel prices. Your total depends on how much you drive and on local prices; see fuel cost by state.

Which has the better fuel economy rating, the BMW X3 or the Mercedes-Benz GLC-Class?

The BMW X3 is rated 29 MPG combined against 27 MPG for the Mercedes-Benz GLC-Class. City: 27 MPG vs 24 MPG. Highway: 33 MPG vs 32 MPG. These are the EPA ratings of each model's lowest-cost configuration.

How is the annual fuel cost calculated?

Distance of 15,000 miles a year at the EPA combined rating (55% city, 45% highway). Gasoline is priced at $4.36/gal (EIA U.S. average for regular, Sep 2026) and electricity at 18.3¢/kWh (EIA U.S. residential average, Jul 2026); premium and diesel configurations use their own EIA prices. Each result is rounded to $10, and differences are calculated from the rounded figures.

Are the BMW X3 and the Mercedes-Benz GLC-Class in the same class?

The EPA classes the BMW X3 as Small SUVs and the Mercedes-Benz GLC-Class as Wagons, so they are listed as rivals.

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More comparisons

EPA ratings: fueleconomy.gov file of Sep 29, 2026 · Prices: EIA regular gasoline, U.S. avg, Sep 2026 ($4.36/gal); residential electricity, U.S. avg, Jul 2026 (18.3¢/kWh) · 15,000 mi/yr, 55% city, same prices for both vehicles