2025 Audi RS Q8 vs 2026 Mercedes-Benz GLS

$136,200 · Crossover

$90,250 · Crossover

Comparison Overview

The most significant numerical divergence between the 2025 Audi RS Q8 and the 2026 Mercedes-Benz GLS is the $45,950 difference in MSRP, with the RS Q8 starting at $136,200 against the GLS's $90,250. Performance metrics also show a dramatic separation, as the RS Q8 generates 631 hp and 627 lb-ft of torque, dwarfing the GLS's 375 hp and 369 lb-ft of torque. Conversely, the GLS offers superior efficiency, achieving 21 combined MPG compared to the RS Q8's 16 combined MPG. Size presents another contrast: the GLS is longer at 205.0 inches and taller at 71.8 inches, while the RS Q8 leads in available storage with 33 cu ft of cargo capacity versus the GLS's 17.4 cu ft. The power advantage of Car 1 is undeniable, yet Car 2 establishes clear supremacy in long-term running costs due to its higher efficiency.

Size Comparison

Performance

Fuel Efficiency

Full Specifications

Our Verdicts

🚗 Best for Commuters

2026 Mercedes-Benz GLS

The 2026 Mercedes-Benz GLS offers a 5 MPG advantage in combined fuel economy (21 MPG vs. 16 MPG), resulting in lower operational costs for daily driving.

👨‍👩‍👧‍👦 Best for Families

2025 Audi RS Q8

The 2025 Audi RS Q8 provides significantly more usable cargo space at 33 cu ft compared to the GLS's 17.4 cu ft.

🏎️ Best for Enthusiasts

2025 Audi RS Q8

The RS Q8 delivers 631 horsepower and 627 lb-ft of torque, vastly outpacing the GLS's 375 hp and 369 lb-ft.

💰 Best Value

2026 Mercedes-Benz GLS

The GLS provides a substantially lower entry price point at $90,250 while still offering AWD capability.

Choose the Audi RS Q8 if...

Maximum outright performance is prioritized, given the RS Q8's 631 hp engine.
A larger cargo area of 33 cubic feet is necessary for utility.
The driver seeks the high-output specifications associated with an MSRP of $136,200.

Choose the Mercedes-Benz GLS if...

Fuel efficiency is a critical factor, evidenced by its 21 combined MPG rating.
A lower initial purchase price of $90,250 is desired.
A larger overall physical footprint, measuring 205.0 inches in length and 71.8 inches in height, is preferred.

Key Dimensions

Dimension	Audi RS Q8	Mercedes-Benz GLS
Length	197.7"	205.0"
Width	79.0"	79.9"
Height	67.5"	71.8"
Wheelbase	117.9"	123.4"

Features Comparison

Safety

Feature	Audi	Mercedes-Benz
Blind Spot Monitor	✓	✓
Lane Departure Warning	✓	✓
Lane Keeping Assist System	✓	✓
Rear Cross Traffic Alert	✓	✓
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
Brake Assist	✓	✓
Tire Pressure Monitoring System	✓	✓
Automatic Headlights	✓	✓
Headlight Delay-Off	✓	✓
LED Headlights	✓	✓
Daytime Running Lights	✓	✓
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	✓	✓
Front Cross Traffic Alert	—	✓
Driver Attention Alert	—	✓
Third Row Head Airbags	—	✓
Brake Drying	—	✓
Front Ventilated Disc Brakes	—	✓
Rear Ventilated Disc Brakes	—	✓
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	631 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)	14/20 MPG	19/24 MPG
EPA Fuel Economy (Combined)	16 MPG	21 MPG
EPA Driving Range (City/Highway)	315.0/450.0 mi.	452.2/571.2 mi.
Fuel Tank Capacity	22.5 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 with Side Sensing	✓	—
Wireless Charging Pad	✓	✓
Adaptive 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	—	✓
Rear Parking Sensors	—	✓
Automatic Parking Assist	—	✓
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	—
Stereo Power	730W	590W
Speaker System	17	13
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
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	37.1 in.	39.4 in.
Front Leg Room	41.3 in.	40.3 in.
Front Shoulder Room	59.5 in.	59.3 in.
Seat Material: Premium Leather	✓	—
Front Seat Type: Sport	✓	—
Driver Seat Power Adjustments	8-way	10-way
Driver Seat Height Adjustment	✓	✓
Driver Seat Lumbar Support	Power	Power
Driver Seat Memory Settings	2	3
Passenger Seat Power Adjustments	8-way	10-way
Passenger Seat Height Adjustment	✓	✓
Passenger Seat Lumbar Support	Power	Power
Passenger Seat Memory Settings	2	3
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	—	✓

Rearseats

Feature	Audi	Mercedes-Benz
Rear Head Room	38.1 in.	40.2 in.
Rear Leg Room	40.2 in.	41.9 in.
Rear Shoulder Room	58.4 in.	58.5 in.
Split-Folding Rear Seatback	✓	✓
Reclining Rear Seats	✓	✓
Folding Center Armrest	✓	✓
Rear Hip Room	—	60.0 in.
Power Folding Third Row Seat	—	✓

Tires and Wheels

Feature	Audi	Mercedes-Benz
Wheel Material	Alloy	Alloy
Wheel Diameter	22 in	—
Tire Type	Performance	All Season
Tire Size	295/40R22	315/40R21
Wheel Size	—	21 x 11.0 in.
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 Q8 and 2026 Mercedes-Benz GLS.

What is the primary powertrain difference between the 2025 Audi RS Q8 and the 2026 Mercedes-Benz GLS?

The Audi RS Q8 is significantly more powerful, generating 631 hp and 627 lb-ft of torque. In contrast, the Mercedes-Benz GLS produces 375 hp and 369 lb-ft of torque, highlighting the RS Q8's performance focus.

How does the fuel economy impact the long-term cost of ownership?

The GLS is considerably more economical, achieving 21 combined MPG compared to the RS Q8's 16 combined MPG. This 5 MPG difference will translate to substantial annual savings on premium unleaded fuel for the GLS owner.

Which crossover offers better utility based strictly on provided measurements?

The Audi RS Q8 offers superior utility by volume, providing 33 cu ft of cargo capacity. The GLS has a considerably smaller cargo area at 17.4 cu ft.

Is there a significant price gap separating these two SUVs?

Yes, the MSRP gap is substantial; the 2025 Audi RS Q8 is listed at $136,200, which is exactly $45,950 more than the 2026 Mercedes-Benz GLS's $90,250 starting price.

Do both vehicles utilize similar transmissions?

Both vehicles use shiftable automatics, but the GLS employs a 9-speed unit, whereas the RS Q8 uses an 8-speed transmission.

Which vehicle has a larger physical stance?

The 2026 Mercedes-Benz GLS has a larger exterior profile overall, measuring 205.0 inches long and 71.8 inches high, while the RS Q8 measures 197.7 inches long and 67.5 inches high.