2026 BMW 3 Series M340i xDrive vs 2026 Mercedes-Benz C-Class AMG C 43
7 mpg better and 29 more lb-ft torque vs 30 more hp. That is the real fork. Key numbers: 386 vs 416 hp, 29 vs 22 MPG.
The 3 Series M340i xDrive leads on 7 MPG better, 29 more lb-ft torque. The C-Class AMG C 43 leads on 30 more hp. The spec table compares 6 specifications head to head.
Key Differences at a Glance
What's Actually Different
These two vehicles differ in 6 specifications.
Full Specification Comparison
Specifications and pricing reflect available data as of early 2026 and may not match current manufacturer figures. Always confirm details with an authorized dealer before making a purchase decision.
| Spec | 2026 BMW 3 Series M340i xDrive | 2026 Mercedes-Benz C-Class AMG C 43 |
|---|---|---|
| Pricing | ||
| MSRP | $64,300 | $64,150 |
| Powertrain | ||
| Engine | 3.0L I6 mild-hybrid Turbo | 2.0L I4 mild-hybrid Turbo |
| Horsepower | 386 hp | 416 hp |
| Torque | 398 lb-ft | 369 lb-ft |
| Transmission | 8-speed shiftable automatic | 9-speed shiftable automatic |
| Drivetrain | AWD | AWD |
| Fuel Economy | ||
| City MPG | 26 | 19 |
| Highway MPG | 33 | 27 |
| Combined MPG | 29 | 22 |
| Fuel Tank | 15.6 gal | 17.4 gal |
| Annual Fuel Cost (EPA) | $2,000/yr | No published data |
| Dimensions | ||
| Curb Weight | 4,008 lbs | 4,165 lbs |
| Wheelbase | 112.2" | 112.8" |
| Length | 185.9" | 188.6" |
| Width | 71.9" | 74.4" |
| Height | 56.7" | 57.1" |
| Safety | ||
| NHTSA Overall | 5/5 stars | No published data |
| IIHS Award | No published data | TSP+ |
| Warranty | ||
| Bumper-to-Bumper | 4yr/50k | 4yr/50k |
| Powertrain | 4yr/50k | 4yr/50k |
| Corrosion | 12yr/unlimited | 4yr/50k |
| Roadside Assistance | 4yr/unlimited | 4yr/50k |
Frequently Asked Questions
What is the price difference between the 2026 BMW 3 Series M340i xDrive and 2026 Mercedes-Benz C-Class AMG C 43?
The 2026 Mercedes-Benz C-Class AMG C 43 starts at $64,150, $150 less than the 2026 BMW 3 Series M340i xDrive at $64,300. That gap is small enough that monthly payments are nearly identical. Focus on which vehicle fits your life, not the sticker.
Who should choose the 2026 BMW 3 Series M340i xDrive?
The 2026 BMW 3 Series M340i xDrive is the stronger pick when lower running costs matter to you, roughly $461/year less on fuel.
Who should choose the 2026 Mercedes-Benz C-Class AMG C 43?
The 2026 Mercedes-Benz C-Class AMG C 43 is the stronger pick when you want to keep $150 in your pocket and the 2026 Mercedes-Benz C-Class AMG C 43 covers your needs; the extra 30 hp matters for your commute or driving style.
Which gets better fuel economy, the 2026 BMW 3 Series M340i xDrive or 2026 Mercedes-Benz C-Class AMG C 43?
The 2026 BMW 3 Series M340i xDrive rates 29 combined MPG, 7 MPG ahead.
Which is more powerful, the 2026 BMW 3 Series M340i xDrive or 2026 Mercedes-Benz C-Class AMG C 43?
The 2026 Mercedes-Benz C-Class AMG C 43 produces 416 hp, 30 more than the 2026 BMW 3 Series M340i xDrive at 386 hp. The 2026 BMW 3 Series M340i xDrive also leads in torque at 398 lb-ft vs 369 lb-ft. The 2026 BMW 3 Series M340i xDrive runs a 3.0L I6 mild-hybrid Turbo; the 2026 Mercedes-Benz C-Class AMG C 43 uses a 2.0L I4 mild-hybrid Turbo.
Is the 2026 BMW 3 Series M340i xDrive bigger than the 2026 Mercedes-Benz C-Class AMG C 43?
The 2026 Mercedes-Benz C-Class AMG C 43 is 2.7″ longer at 188.6″ vs 185.9″. The 2026 Mercedes-Benz C-Class AMG C 43 has a 0.6″ longer wheelbase, which typically means more rear-seat legroom.
How do the warranties compare?
Both offer similar warranty coverage: 4yr/50k bumper-to-bumper and 4yr/50k powertrain.
Explore more: BMW trims, BMW 3 Series trims, Mercedes-Benz trims, Mercedes-Benz C-Class trims
The 3 Series–C-Class Decision
Shopping compact cars means the 3 Series and C-Class will likely end up on the same test-drive day. Here is what the numbers say before you get behind the wheel. The $-150 price gap works out to less than $10/month on a typical loan, so the cost difference is negligible. Pick on fit, not on price.
What Powers Each Vehicle
The 2026 BMW 3 Series M340i xDrive runs a 3.0L I6 mild-hybrid Turbo; the 2026 Mercedes-Benz C-Class AMG C 43 uses a 2.0L I4 mild-hybrid Turbo. The 2026 Mercedes-Benz C-Class AMG C 43 has 30 more hp (416 vs 386), enough to notice on highway on-ramps and when passing. Both use AWD.
The Ownership Math
The 2026 BMW 3 Series M340i xDrive saves roughly $461/year on fuel at $3.50/gallon and 12,000 annual miles. Over five years, that is $2,305.
The Decision
Choose the 2026 BMW 3 Series M340i xDrive when lower running costs matter to you, roughly $461/year less on fuel. Choose the 2026 Mercedes-Benz C-Class AMG C 43 when you want to keep $150 in your pocket and the 2026 Mercedes-Benz C-Class AMG C 43 covers your needs.
Specifications shown combine licensed third-party automotive data with official manufacturer, EPA, and NHTSA source material. Actual pricing, features, and availability may vary by region and dealer. Always confirm details with an authorized dealer before making a purchase decision. TrimAtlas is not affiliated with BMW or Mercedes-Benz or any dealership.