Three German sport midsize sedans. Three stickers within about a grand: Audi S5 from $63,300, BMW M340i xDrive from $64,300, Mercedes-AMG C 43 from $64,150. Same shopping list. Different personalities. Here is the U.S. OEM math without the brochure fog.
Money on the window
Audi USA lists the 2026 S5 from $63,300.
BMW USA lists the M340i xDrive Sedan from $64,300.
Mercedes-Benz USA prices the AMG C 43 Sedan from $64,150.
The Audi undercuts both by about $850–$1,000 before destination. The AMG and BMW almost stack. Destination, taxes, and options are not in those numbers — check the build you actually order.
Power and pace
The Audi S5 is the turbo V6 brief: 362 hp, 406 lb-ft, seven-speed S tronic, standard quattro. Audi’s 0–60 claim: 4.3 seconds.
BMW’s M340i xDrive is the M TwinPower Turbo inline-6 with 48V mild-hybrid help: 386 hp. BMW AG’s preliminary 0–60 claim: 4.1 seconds. xDrive is standard on this trim. Official U.S. pages cited below do not put a clean torque or curb-weight figure on the M340i card, so those cells stay off the sheet rather than guessed.
Mercedes-AMG’s C 43 pairs a handcrafted AMG 2.0L inline-4 with hybrid assist and an electric exhaust-gas turbocharger: 416 hp and 369 lb-ft. Published 0–60: 4.3 seconds. Transmission is AMG SPEEDSHIFT MCT 9-speed; drivetrain is AMG Performance 4MATIC. Mercedes lists curb weight at 4,165 lbs.
OEM horsepower: AMG leads. OEM 0–60: BMW owns the quickest claim. The Audi trades peak hp for the lowest sticker and a six-cylinder you feel every morning.
Character — and the honest downsides
S5: daily AWD comfort with quattro and that V6. Honest downside — less peak horsepower than both rivals on the OEM cards.
M340i xDrive: M-lite thrills — quickest published sprint here, mild-hybrid I6, sport-sedan focus. Cabin can feel colder and more clinical than the Audi if you want warmth over sharpness.
C 43: AMG character and the four-cylinder turbo personality with e-turbo assist. Peak hp wins the table. Enthusiasts will still argue four-cyl vs six-cyl in a sport sedan that starts near $64k.
Who should buy which
Take the Audi S5 if you want the lowest sticker in this set, quattro everyday confidence, and a turbo V6 that still sounds like a proper German sport sedan — knowing 362 hp trails both rivals.
Take the BMW M340i xDrive if the 4.1-second claim and M-lite thrills matter more than beating the Audi on price — 386 hp mild-hybrid I6, xDrive, and the sharpest published pace here.
Take the Mercedes-AMG C 43 if 416 hp, AMG SPEEDSHIFT, and that e-turbo four-cylinder story win — accepting the four-vs-six argument and a sticker that sits between the Audi and the BMW.
Prices exclude destination, taxes, and options. Specs are manufacturer claims for comparison; verify the build you actually order.
Spec sheet
Manufacturer claims from the OEM pages linked below — verify the build you order.
| Spec | Audi S5 | BMW M340i xDrive | Mercedes-AMG C 43 |
|---|---|---|---|
| Starting MSRP | $63,300 | $64,300 | $64,150 |
| Power | 362 hp | 386 hp | 416 hp |
| Torque | 406 lb-ft | — | 369 lb-ft |
| 0–60 mph | 4.3 s (Audi claim) | 4.1 s (BMW AG preliminary) | 4.3 s |
| Engine | Turbo V6 | 3.0L I6 mild-hybrid (M TwinPower Turbo) | Handcrafted AMG 2.0L I4 + hybrid assist / e-turbo |
| Transmission | 7-speed S tronic | — | AMG SPEEDSHIFT MCT 9-speed |
| Drivetrain | quattro | xDrive | AMG Performance 4MATIC |
| Curb weight | — | — | 4,165 lbs |
Sources:
- Audi USA — 2026 S5 overview
- BMW USA — 3 Series Sedan M models (M340i xDrive MSRP / hp / 0–60)
- BMW USA — 3 Series Sedan overview
- Mercedes-Benz USA — AMG C 43 Sedan
- Audi MediaCenter — Image No. A244460
- BMW PressClub — Image No. P90583902
- Mercedes-Benz USA — C 43 Sedan imagery
Official photography © AUDI AG, © BMW AG, © Mercedes-Benz AG — editorial use.