Vehicle comparison
BMW 3 Series (330i) vs Mercedes-Benz C-Class (C300)
Side-by-side fuel and ownership cost comparison. Estimates use 12,000 mi/year at average US gas prices.
- Updated for 2026
- EPA-style MPG
- US avg fuel prices
- US units
- Transparent assumptions
Lowest running cost
BMW 3 Series (330i) wins on fuel cost
At 12,000 miles per year, the BMW 3 Series (330i) costs about $1640 per year, roughly $117 less than the Mercedes-Benz C-Class (C300). Over 5 years, that's about $586 in fuel savings.
Spec & cost comparison
MPG/MPGe figures are estimates based on typical recent model years.
| Spec | BMW 3 Series (330i) | Mercedes-Benz C-Class (C300) |
|---|---|---|
| Type | SEDAN | SEDAN |
| Fuel | Premium gas | Premium gas |
| City MPG/MPGe | 26 | 24 |
| Highway MPG/MPGe | 36 | 35 |
| Combined MPG/MPGe | 30 | 28 |
| Tank / Battery | 15.6 gal | 17.4 gal |
| Energy cost | $4.10/gal | $4.10/gal |
| Cost per mile | $0.137 | $0.146 |
Annual cost at 8k / 12k / 15k miles
Estimated yearly fuel spend at common US mileage levels.
| Miles/year | BMW 3 Series (330i) | Mercedes-Benz C-Class (C300) | Difference |
|---|---|---|---|
| 8,000 | $1093/yr · $91/mo | $1171/yr · $98/mo | $78 (BMW 3 Series (330i)) |
| 12,000 | $1640/yr · $137/mo | $1757/yr · $146/mo | $117 (BMW 3 Series (330i)) |
| 15,000 | $2050/yr · $171/mo | $2196/yr · $183/mo | $146 (BMW 3 Series (330i)) |
Estimates only. Real costs depend on driving style, terrain, local gas/electricity prices and weather.
Which one is best for…
Best for commuting
BMW 3 Series (330i)
Highest combined MPG/MPGe and lowest cost per mile means cheaper daily driving.
See BMW 3 Series (330i)Best for road trips
BMW 3 Series (330i)
Better highway efficiency, larger tank/battery and longer range between stops.
See BMW 3 Series (330i)Best for families
BMW 3 Series (330i)
SUVs, minivans and three-row vehicles win on space and child-seat flexibility.
See BMW 3 Series (330i)Best for lowest running cost
BMW 3 Series (330i)
Cheaper energy use and lower cost per mile at every common mileage tier.
See BMW 3 Series (330i)How we compare these vehicles
- Annual mileage
- Modeled at 12,000 mi/yr unless a scenario specifies otherwise.
- Cost per mile
- $/gal ÷ MPG, or $/kWh ÷ (MPGe ÷ 33.7) for EVs.
- EV vs gas
- Compared at average US gas and residential electricity prices — fast-charging can be 2–3× higher.
- Maintenance
- Fuel cost only — EVs typically save another $400–$1,000/yr in service and brake wear.
Sources & assumptions
- EPA fuel economy data — City / highway / combined MPG and MPGe baselines.
- U.S. Department of Energy (fueleconomy.gov) — Vehicle efficiency and EV range references.
- AAA gas price trends — Recent national and regional retail fuel averages.
- EIA electricity rates — Average residential per-kWh prices used for EV charging.
We summarize publicly available data — no scraping, no external API calls. Figures are calibrated periodically; use the calculators above for your exact inputs.
Frequently asked questions
Which is cheaper to drive, the BMW 3 Series (330i) or Mercedes-Benz C-Class (C300)?
At 12,000 miles per year, the BMW 3 Series (330i) costs about $1640 per year vs $1757 for the Mercedes-Benz C-Class (C300) — roughly $117 less per year.
What's the MPG difference between the BMW 3 Series (330i) and Mercedes-Benz C-Class (C300)?
The BMW 3 Series (330i) is rated around 30 combined MPG versus 28 MPG for the Mercedes-Benz C-Class (C300). Highway figures are 36 vs 35.
How much will I spend on fuel over 5 years?
Driving 12,000 miles a year for five years, expect about $8200 for the BMW 3 Series (330i) and $8786 for the Mercedes-Benz C-Class (C300), a difference of roughly $586.
Is the BMW 3 Series (330i) or Mercedes-Benz C-Class (C300) better for commuting?
For pure cost per mile, the BMW 3 Series (330i) wins. EVs charged at home typically deliver the lowest commuting cost, followed by hybrids and efficient compacts.
Which one is better for road trips?
BMW 3 Series (330i) is generally the better road-trip choice — gas and hybrid vehicles win on long highway routes thanks to faster refueling, while EVs work best when charging stops fit your route.
Are these fuel cost numbers accurate for my driving?
They're estimates based on EPA-style combined MPG and average US gas prices. Real-world cost depends on local fuel prices, driving style, terrain, weather and how much city vs highway driving you do.