2020 Mercedes-Benz GLC300 MPG & Specs — Real-World vs EPA, All Trims
Every gas trim of this model takes premium.
Is the 2020 Mercedes-Benz GLC300 good on gas?
At up to 24 MPG combined, the 2020 Mercedes-Benz GLC300 is worse than average for a Small Sport Utility Vehicle 2WD — that class averages about 26.2 MPG across 1,092 EPA-tested versions, so it's on the thirsty side for its size.
Real-world MPG vs the EPA number
The EPA figures above come from a standardized dynamometer test, not the open road — real-world MPG typically runs a bit lower depending on your driving, climate and terrain. That's true of every car on this site, old or new.
At today's AAA national average price — $4.68/gal for premium gas as of 2026-07-05 — the most efficient trim runs about $2,925/year (roughly $244/month, about $19.50 per 100 miles) at the EPA's assumed 15,000 miles/year, using an estimated 625 gallons a year. We don't estimate a cost-per-fill since exact tank size isn't in the public EPA dataset, but the per-100-mile figure scales to any tank. Current national average gas prices →
2020 Mercedes-Benz GLC300 trims & fuel economy
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr (today's price) |
|---|---|---|---|
| 2.0L 4-cyl, Automatic 9-spd, RWD | PREMIUM | 24 | $2,925 |
2020 Mercedes-Benz GLC300 specs
What the EPA test-car listings record for this model year — every combination sold is a row in the trims table above.
| Engine options | 2.0L 4-cyl turbo |
| Transmission | Automatic 9-spd |
| Drive type | RWD |
| EPA body class | Small Sport Utility Vehicle 2WD |
| Fuel | Premium |
| Tailpipe CO₂ | 366 g/mi |
Other years of the Mercedes-Benz GLC300
Similar cars (Small Sport Utility Vehicle 2WD)
Cars that take premium · Cheapest cars to fuel · Where fuel grade depends on the trim · Fuel guides
1 trim(s) · EPA FuelEconomy.gov data retrieved 2026-10-25 · fuel prices AAA national average as of 2026-07-05.