2026 Audi RS 6 vs 2026 Mercedes-Benz GLS

$130,700 · Wagon

$90,250 · Crossover

Comparison Overview

Deciding between raw performance utility and luxury family hauling often stumps buyers, especially when facing these two German titans. The 2026 Audi RS 6, a performance wagon, commands an MSRP of $130,700 and boasts a potent 621 hp, making it the clear choice for speed enthusiasts. Conversely, the 2026 Mercedes-Benz GLS starts significantly lower at $90,250 and offers a more practical Crossover body style. While the Audi delivers 627 lb-ft of torque, its 16 combined MPG trails the GLS's 21 combined MPG, resulting in a notable 5 MPG difference. The GLS also offers superior size, measuring 205.0 inches long compared to the RS 6's 196.7 inches, balancing its 375 hp with everyday usability. This comparison boils down to whether you prioritize that extra 246 hp deficit for thrilling drives or superior fuel economy and size for daily life.

Size Comparison

Performance

Fuel Efficiency

Full Specifications

Our Verdicts

🚗 Best for Commuters

2026 Mercedes-Benz GLS

The Mercedes-Benz GLS wins for commuting due to its superior fuel efficiency, achieving 21 combined MPG versus the Audi's 16 MPG.

👨‍👩‍👧‍👦 Best for Families

2026 Mercedes-Benz GLS

The GLS offers better family utility with a larger, more traditionally accommodating Crossover body style and greater overall length.

🏎️ Best for Enthusiasts

2026 Audi RS 6

The Audi RS 6 clearly caters to enthusiasts with its massive 621 hp and 627 lb-ft of torque output.

💰 Best Value

2026 Mercedes-Benz GLS

The Mercedes-Benz GLS offers vastly more usability for a $40,450 lower starting price.

Choose the Audi RS 6 if...

You absolutely need 621 horsepower on tap for aggressive driving.
You prefer the unique, low-slung styling and handling characteristics of a high-performance wagon.
You only drive sparingly, as you can tolerate the lower 14 MPG city fuel economy.

Choose the Mercedes-Benz GLS if...

Your primary concern is saving $40,450 on the initial purchase price.
You need better efficiency, specifically the 21 combined MPG rating.
You require maximum passenger and overall volume that the larger 205.0-inch long Crossover provides.

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 Fixed 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	—	✓
Rear Height 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]	✓	—
Hill Descent Control	✓	✓
Center Differential Type	—	Limited Slip

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)	16 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.
Complimentary Scheduled Maintenance	3 yr./ 30000 mi.	—
Hybrid Component Warranty	—	6 yr./ 62000 mi.

Frequently Asked Questions

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

What is the real-world impact of the difference in fuel economy?

The 2026 Audi RS 6 gets 16 combined MPG, while the Mercedes-Benz GLS achieves 21 combined MPG; this 5 MPG gap means the GLS will cost significantly less to operate during routine driving, especially since both require premium fuel.

How does the power difference affect daily driving versus track performance?

The Audi RS 6 has 246 more horsepower (621 hp vs. 375 hp), meaning it will feel dramatically quicker in sprints and performance driving, while the GLS provides adequate power for freeway merging.

Does the Audi RS 6 have better cargo space than the larger Mercedes-Benz GLS?

Surprisingly, yes, the Audi RS 6 wagon offers 29.9 cu ft of cargo space, significantly more than the Crossover GLS’s 17.4 cu ft, even though the GLS is physically a taller and longer vehicle.

Which vehicle is physically larger for parking and maneuverability?

The Mercedes-Benz GLS is the physically larger vehicle, measuring 205.0 inches long and 79.9 inches wide, compared to the Audi RS 6's 196.7-inch length and 76.8-inch width, making the Audi easier to navigate tight spaces.

Is the high cost of the Audi justified by its performance specs?

The Audi RS 6 costs $130,700 versus $90,250 for the GLS. This $40,450 premium buys you significantly more power (621 hp) but sacrifices overall practicality and efficiency.

Are the transmissions fundamentally different between these two AWD vehicles?

Yes, the Audi uses an 8-speed shiftable automatic transmission geared for aggressive shifts, whereas the Mercedes-Benz GLS features a 9-speed unit optimized for smoother operation and efficiency.