The Mercedes E450 won Car and Driver’s four-way luxury sedan test for comfort plus grip. The BMW 540i xDrive owns the sprint at 4.1 seconds to 60. The Audi A6 quattro undercuts both on base price and beat the BMW head-to-head. Stickers start about $8k apart: A6 from $65,395, 540i from $69,150, E450 from $73,650 (2026 bases as published by Car and Driver). Pick your trade-offs before the options page eats the gap.
Money on the window
Car and Driver’s 2026 A6 test car started at $65,395, cheapest of this trio. Prestige plus Exclusive Design pushed their as-tested sticker to $84,970.
The 540i xDrive opened at $69,150. Their Alpine White tester landed at $81,300, the lowest as-tested of the four-door luxury set C&D later ran.
Mercedes listed the E450 from $73,650. Load Pinnacle, air springs, rear-axle steering, and the MBUX Superscreen and C&D’s car hit $95,375, about $10k above the next-priciest participant.
Buyer rule: if your as-tested budget sits under about $85k, the A6 and 540i are the realistic lane. The loaded E450 clears $90k fast. Destination, taxes, and options are not in those base numbers. Current OEM configurator pages already show 2027 MSRP drift, so confirm the year and build before you wire a deposit.
Power and pace
The Audi runs a turbo 3.0-liter V6: 362 hp, 406 lb-ft, seven-speed dual-clutch, standard quattro. C&D clocked 4.3 seconds to 60. MotorTrend’s first tests landed closer to mid-4s depending on steel vs air suspension. Still quick for a business sedan.
BMW’s 540i pairs a turbo inline-6 with 48-volt mild-hybrid help: 375 hp and 398 lb-ft, eight-speed automatic, standard xDrive. C&D’s instrumented run: 4.1 seconds, quickest of this three. BMW USA’s preliminary claim sits at 4.4 seconds.
Mercedes answers with its own turbo inline-6 mild hybrid: 375 hp, 369 lb-ft, 9G-TRONIC nine-speed, 4MATIC. C&D measured 4.5 seconds to 60; Mercedes lists a 4.4-second claim on the E450 card.
On paper the BMW owns the sprint. In C&D’s four-way luxury test the E450 still took the overall win for how it mixes comfort and grip. The A6 beat the 540i head-to-head and was the dark horse athlete when all four doors lined up.
Character
Option the A6’s air suspension and you get plush ride with accurate steering, plus the easiest infotainment of this German set. Skip those boxes and the sedan still feels composed, but the cabin and chassis don’t fully sing until Prestige and the better seats show up. Two real costs: the exterior is easy to forget in a hotel driveway, and Prestige plus Exclusive Design inflate the sticker into the mid-$80ks. Owner mistake: ordering base seats to “save money,” then living with a cabin that never matches the chassis.
The 540i’s powertrain is the star. Silky on a cruise, loud when asked, and efficient enough that the mild hybrid isn’t just a brochure line. C&D still called the steering and chassis feel numb, and seats plus menus frustrated more than one editor. Decision rule: if numb steering bothers you on a long interstate, skip the 540i for this generation and shop the A6 or E450 instead. The badge’s old road-chatter promise isn’t here.
The E450 feels vault-solid over broken pavement and still put 0.92 g on C&D’s skidpad. That silken six does the quiet work. Testers disliked MBUX menus and capacitive wheel controls, and a loaded car clears $90k without trying. Decision rule: pay the E450 premium only if comfort-plus-grip is the reason you’re in this segment. If you mainly want the quickest 0–60 and a lower as-tested number, the 540i already won that fight.
Who should buy which
Take the Audi A6 if you want the lowest opening sticker, quattro everyday confidence, and a sedan that actually engages on a back road. Budget for air springs and the seats that make the cabin work. Walk away if you need trunk space north of 14 cu ft or refuse to option the suspension.
Take the BMW 540i xDrive if the inline-six and the quickest C&D sprint matter more than beating the Audi on price. Walk away if you want lively steering feel or cooler seats than C&D’s editors got. The powertrain earns the badge; the chassis chatter does not.
Take the Mercedes-Benz E450 if C&D’s overall luxury winner and comfort-with-bite matter more than the base undercut. Walk away if you hate capacitive switches, need the cheapest as-tested build, or can’t stretch past the low-$90ks once options land.
Ownership costs beyond the sticker are thin in the public record we used for this piece. [VERIFY: typical 3-year maintenance / warranty coverage / tire replacement costs for A6 V6, 540i xDrive, and E450 4MATIC before you commit.] Prices exclude destination, taxes, and options. Specs mix OEM claims and C&D measured figures as noted on the sheet. Verify the build you actually order.
Spec sheet
2026 base MSRPs and curb weights as published in Car and Driver’s comparisons; power, torque, gearboxes, and drivetrains match OEM cards. 0–60 times are C&D instrumented. BMW USA’s preliminary claim for the 540i is 4.4 s; Mercedes lists the E450 at 4.4 s. Verify the build you order.
| Spec | Audi A6 | BMW 540i xDrive | Mercedes-Benz E450 |
|---|---|---|---|
| Starting MSRP | $65,395 | $69,150 | $73,650 |
| Power | 362 hp | 375 hp | 375 hp |
| Torque | 406 lb-ft | 398 lb-ft | 369 lb-ft |
| 0–60 mph | 4.3 s (C&D) | 4.1 s (C&D) | 4.5 s (C&D) |
| Engine | Turbo 3.0L V6 | Turbo 3.0L I6 mild-hybrid | Turbo 3.0L I6 mild-hybrid |
| Transmission | 7-speed dual-clutch | 8-speed automatic | 9G-TRONIC 9-speed |
| Drivetrain | quattro | xDrive | 4MATIC |
| Curb weight | 4,434 lb (C&D) | 4,316 lb (C&D) | 4,468 lb (C&D) |
| Trunk | 14 cu ft | 18 cu ft | 13 cu ft |
Comparing new stickers is only half the job. If a used A6, 5 Series, or E-Class is also on the shortlist, grab our free Audi PPI Checklist — a short driveway buyer’s guide before you wire the deposit.
Sources:
- Car and Driver — 2026 Audi A6 vs BMW 540i comparison
- Car and Driver — A6 / 540i / Genesis G80 / Mercedes E450 luxury sedan comparison
- MotorTrend — 2026 Audi A6 first test
- Audi USA — A6 Sedan overview
- BMW USA — 5 Series Sedan overview (540i xDrive)
- Mercedes-Benz USA — E 450 4MATIC Sedan
- Audi MediaCenter — Image No. A263923
- Audi MediaCenter — Image No. A250409
- BMW PressClub — Image No. P90605368
- Mercedes-Benz USA — E450 Sedan imagery
Official photography © AUDI AG, © BMW AG, © Mercedes-Benz AG — editorial use.