2025 Audi RS 6 vs 2026 Mercedes-Benz GLS

$126,600 · Wagon

$90,250 · Crossover

Comparison Overview

The 2025 Audi RS 6 wagon detonates onto the scene, delivering a staggering 621 horsepower and 627 lb-ft of torque, transforming the mundane estate into a performance monster ready to assault the asphalt. In stark contrast, the 2026 Mercedes-Benz GLS offers civilized capability, serving as a luxurious, family-focused three-row Crossover prioritizing space over sheer speed. The power differential is immense: the RS 6 boasts 246 more horsepower than the GLS's 375 hp output. However, practicality shifts the balance; the GLS achieves 21 MPG combined versus the Audi's thirsty 17 MPG combined. With an MSRP gap of $36,350, the GLS provides substantial savings, yet the RS 6, priced at $126,600, delivers supercar performance in a practical shell, contrasting sharply with the GLS's commanding size (205.0 inches long versus the Audi's 196.7 inches).

Size Comparison

Performance

Fuel Efficiency

Full Specifications

Our Verdicts

🚗 Best for Commuters

2026 Mercedes-Benz GLS

The 2026 Mercedes-Benz GLS offers a more palatable 21 MPG combined efficiency for daily driving compared to the RS 6's 17 MPG combined.

👨‍👩‍👧‍👦 Best for Families

2026 Mercedes-Benz GLS

The GLS is a dedicated Crossover designed for family hauling, possessing a greater overall height and volume capacity than the lower-slung RS 6 wagon.

🏎️ Best for Enthusiasts

2025 Audi RS 6

The 2025 Audi RS 6 dominates with a breathtaking 621 hp and 627 lb-ft of torque, promising an exhilarating driving experience.

💰 Best Value

2026 Mercedes-Benz GLS

The Mercedes-Benz GLS saves buyers $36,350 on the sticker price while still offering a respectable 375 horsepower.

Choose the Audi RS 6 if...

You prioritize explosive acceleration, leveraging the RS 6's massive 621 horsepower output.
You desire a low-slung, aggressive design wrapped around a practical 30 cubic feet of cargo space.
You enjoy the focused driving dynamics of an 8-speed automatic paired with Quattro all-wheel drive.

Choose the Mercedes-Benz GLS if...

Your budget dictates savings, as the GLS undercuts the RS 6 by $36,350.
You require a larger, more upright structure, evidenced by the GLS's 71.8-inch height.
You prioritize fuel economy, benefiting from the GLS's 4 MPG combined advantage (21 MPG vs 17 MPG).

Key Dimensions

Dimension	Audi RS 6	Mercedes-Benz GLS
Length	196.7"	205.0"
Width	76.8"	79.9"
Height	58.6"	71.8"
Wheelbase	115.3"	123.4"

Features Comparison

Safety

Feature	Audi	Mercedes-Benz
Lane Departure Warning	✓	✓
Pre-Collision Safety System	✓	✓
Post-Collision Safety System	✓	✓
Dual Front Side-Mounted Airbags	✓	✓
Dual Rear Side-Mounted Airbags	✓	—
Front Head Airbags	✓	✓
Rear Head Airbags	✓	✓
Passenger Airbag Occupant Sensing Deactivation	✓	✓
Electronic Stability Control	✓	✓
Traction Control System	✓	✓
LATCH System	✓	✓
Rear Door Child Safety Locks	✓	✓
Anti-lock Brakes (ABS)	4-Wheel	4-Wheel
Front Ventilated Disc Brakes	✓	✓
Rear Ventilated Disc Brakes	✓	✓
Brake Assist	✓	✓
Tire Pressure Monitoring System	✓	✓
Automatic Headlights	✓	✓
Headlight Delay-Off	✓	✓
LED Headlights	✓	✓
Daytime Running Lights	✓	✓
Headlight Washers	✓	—
Integrated Turn Signal Mirrors	✓	✓
Front Headrests	2	2
Front Integrated Headrests	✓	—
Rear Headrests	3	3
Rear Height Adjustable Headrests	✓	✓
Rear Center 3-Point Seatbelt	✓	✓
Anti-Theft Alarm System (Remote)	✓	✓
Engine Immobilizer	✓	✓
Blind Spot Monitor	—	✓
Lane Keeping Assist System	—	✓
Front Cross Traffic Alert	—	✓
Rear Cross Traffic Alert	—	✓
Driver Attention Alert	—	✓
Third Row Head Airbags	—	✓
Brake Drying	—	✓
Brake Preparation System	—	✓
Adaptive Headlights	—	✓
Cornering Lights	—	✓
Front Power Adjustable Headrests	—	✓

Engine

Feature	Audi	Mercedes-Benz
Base Engine Displacement	4.0 L	3.0 L
Number of Cylinders	V8	inline 6
Base Engine Type	mild hybrid	mild hybrid
Horsepower	621 hp	375 hp @ 5800 rpm
Torque	627 lb-ft	369 lb-ft @ 1800 rpm
Number of Valves	32	24
Camshaft Type	Double overhead cam (DOHC)	Double overhead cam (DOHC)
Variable Valve Timing	Variable	Variable
Fuel Injection Type	✓	✓

Drive Train

Feature	Audi	Mercedes-Benz
Transmission Type	8-speed shiftable automatic	9-speed shiftable automatic
Drivetrain Type	all wheel drive	all wheel drive
[object Object]	✓	—
[object Object]	✓	—
Center Differential Type	—	Limited Slip
Hill Descent Control	—	✓

Fuel

Feature	Audi	Mercedes-Benz
Fuel Type	premium unleaded (required)	premium unleaded (required)
EPA Fuel Economy (City/Highway)	14/21 MPG	19/24 MPG
EPA Fuel Economy (Combined)	17 MPG	21 MPG
EPA Driving Range (City/Highway)	270.2/405.3 mi.	452.2/571.2 mi.
Fuel Tank Capacity	19.3 gal.	23.8 gal.

Comfort & Convenience

Feature	Audi	Mercedes-Benz
Push Button Start	✓	✓
Power Tilt and Telescopic Steering Wheel	✓	✓
Transmission Controls on Steering Wheel	✓	✓
Audio Controls on Steering Wheel	✓	✓
Electric Power Steering	✓	✓
Front View Camera	✓	✓
Side View Camera	✓	✓
Rear View Camera	✓	✓
Front Parking Sensors	✓	✓
Rear Parking Sensors	✓	✓
Wireless Charging Pad	✓	✓
Cruise Control	✓	—
Universal Remote Transmitter	✓	✓
Front Cupholders	✓	✓
Rear Cupholders	✓	✓
Front Door Pockets	✓	✓
Rear Door Pockets	✓	✓
Front Seatback Storage	✓	✓
Leather Steering Wheel	✓	✓
Heated Steering Wheel	✓	—
Four Zone Climate Control	✓	✓
Rear Ventilation Ducts with Fan Control	✓	✓
Interior Air Filtration	✓	✓
Dual Vanity Mirrors	✓	✓
Auto-Dimming Rearview Mirror	✓	✓
Turn Signal Indicators in Mirrors	✓	✓
Cruise Control on Steering Wheel	—	✓
Automatic Parking Assist	—	✓
Adaptive Cruise Control	—	✓
3rd Row Cupholders	—	✓
Overhead Console with Storage	—	✓
Power Rear Seat Easy Entry	—	✓

In Car Entertainment

Feature	Audi	Mercedes-Benz
Infotainment Display	10.1 in	12.3 in
AM/FM Stereo	✓	✓
Premium Brand Speakers	Bang & Olufsen	—
Surround Audio	Discrete	Discrete
Android Auto (Wireless)	✓	✓
Apple CarPlay (Wireless)	✓	✓
USB Port	✓	✓
USB Port with External Media Control	✓	✓
Satellite Radio	✓	✓
Satellite Radio Trial Period	3 months	6 months
Premium Speaker Brand	—	Burmester
Stereo Power	—	590W
Speaker System	—	13
Subwoofer Count	—	2
Speed Sensitive Volume Control	—	✓

Power Feature

Feature	Audi	Mercedes-Benz
One-Touch Power Windows	4	4
Moonroof Type	1st Row Power Glass Extended	1st Row Power Glass Extended
Keyless Entry	✓	✓
Heated Mirrors	✓	✓
Reverse Tilt Passenger Mirror	—	✓

Frontseats

Feature	Audi	Mercedes-Benz
Front Head Room	38.3 in.	39.4 in.
Front Leg Room	41.3 in.	40.3 in.
Front Shoulder Room	57.8 in.	59.3 in.
Seat Material: Premium Leather	✓	—
Front Seat Type: Sport	✓	—
Driver Seat Power Adjustments	10-way	10-way
Driver Seat Height Adjustment	✓	✓
Driver Seat Lumbar Support	Power	Power
Driver Seat Memory Settings	2	3
Passenger Seat Power Adjustments	10-way	10-way
Passenger Seat Height Adjustment	✓	✓
Passenger Seat Lumbar Support	Power	Power
Driver Seat Heating	Multi-level	Multi-level
Passenger Seat Heating	Multi-level	Multi-level
Driver Seat Ventilation	✓	✓
Passenger Seat Ventilation	✓	✓
Front Hip Room	—	60.8 in.
Seat Material: Leatherette	—	✓
Front Seat Type: Bucket	—	✓
Driver Seat Thigh Extension	—	✓
Passenger Seat Thigh Extension	—	✓
Passenger Seat Memory Settings	—	3

Rearseats

Feature	Audi	Mercedes-Benz
Rear Head Room	39.5 in.	40.2 in.
Rear Leg Room	37.4 in.	41.9 in.
Rear Shoulder Room	56.5 in.	58.5 in.
Split-Folding Rear Seatback	✓	✓
Folding Rear Seat Feature	✓	—
Pass-Thru Center Armrest	✓	—
Rear Hip Room	—	60.0 in.
Reclining Rear Seats	—	✓
Folding Center Armrest	—	✓
Power Folding Third Row Seat	—	✓

Tires and Wheels

Feature	Audi	Mercedes-Benz
Wheel Material	Alloy	Alloy
Wheel Size	21 in	21 x 11.0 in.
Tire Type	Performance	All Season
Tire Size	275/35R21	315/40R21
Spare Tire Type	—	Temporary
Spare Tire Location	—	Inside Mounted

Suspension

Feature	Audi	Mercedes-Benz
Four-Wheel Independent Suspension	✓	✓
Front Stabilizer Bar	✓	✓
Rear Stabilizer Bar	✓	✓

Warranty

Feature	Audi	Mercedes-Benz
Basic Warranty	4 yr./ 50000 mi.	4 yr./ 50000 mi.
Drivetrain Warranty	4 yr./ 50000 mi.	4 yr./ 50000 mi.
Corrosion/Rust Warranty	12 yr./ unlimited mi.	4 yr./ 50000 mi.
Roadside Assistance	4 yr./ unlimited mi.	4 yr./ 50000 mi.
Hybrid Component Warranty	—	6 yr./ 62000 mi.

Frequently Asked Questions

Common questions about comparing the 2025 Audi RS 6 and 2026 Mercedes-Benz GLS.

How much more powerful is the Audi RS 6 compared to the Mercedes-Benz GLS?

The 2025 Audi RS 6 boasts significantly higher output, generating 621 horsepower versus the 2026 Mercedes-Benz GLS's 375 horsepower, resulting in a 246 hp difference.

Which vehicle is better for long-distance commuting in terms of fuel usage?

The Mercedes-Benz GLS is the clear choice for commuters seeking better efficiency, delivering 21 MPG combined, whereas the high-performance RS 6 achieves only 17 MPG combined.

What is the primary difference in size and utility between these two vehicles?

The GLS is larger overall, measuring 205.0 inches long and 71.8 inches tall, designed as a Crossover, while the RS 6 is shorter (196.7 inches) and focuses on a sportier wagon silhouette.

Does the difference in price translate directly to performance gaps?

Yes, the $36,350 price gap favors the GLS on value, but the more expensive RS 6 delivers vastly superior performance metrics, notably 627 lb-ft of torque against the GLS's 369 lb-ft.

Are both vehicles capable of utilizing all-wheel drive?

Both the Audi RS 6 and the Mercedes-Benz GLS are equipped with all-wheel drive systems, ensuring capable traction delivery regardless of which vehicle is chosen.

How does the cargo capacity compare between the wagon and the crossover?

Despite being classified as a wagon, the Audi RS 6 actually offers more maximum cargo capacity at 30 cubic feet compared to the larger Crossover GLS, which provides 17.4 cubic feet.