Genesis G90 vs Mercedes-Benz S-Class: Specs Compared

Also searched as Mercedes-Benz S-Class vs Genesis G90 specs — both orientations show this same side-by-side comparison.

The Mercedes-Benz S-Class is the more efficient of the two: it reaches 26 mpg combined versus 21 mpg for the Genesis G90, a 5 mpg advantage and costs about $700 less per year to fuel.

Across 5 measured categories, the Mercedes-Benz S-Class leads in 5. Figures are EPA test data, not manufacturer claims.

2017–2026

Genesis G90

Large Cars · 32 configurations

21mpg combined (best)
All Genesis G90 specs

2015–2027

Mercedes-Benz S-Class

Large Cars · 106 configurations

26mpg combined (best)
All Mercedes-Benz S-Class specs

Head-to-head specifications

MetricGenesis G90Mercedes-Benz S-Class
Best combined MPG21 mpg26 mpg ✓
Best city MPG18 mpg24 mpg ✓
Best highway MPG26 mpg31 mpg ✓
Lowest annual fuel costEPA estimate at 15,000 miles per year$3,600$2,900 ✓
Lowest CO2 output426 g/mi106 g/mi ✓
Engines offeredSIDI & PFI, SIDI & PFI; Mild Hybrid, SIDISIDI; Mild Hybrid, 6.0, SIDI; PHEV, SIDI
TransmissionsAutomatic (S8)Automatic 9-spd, Automatic 7-spd
DrivetrainsAll-Wheel Drive, Rear-Wheel DriveAll-Wheel Drive, 4-Wheel Drive, Rear-Wheel Drive
Fuel typesPremiumPremium, Premium and Electricity
EPA classLarge CarsLarge Cars
Years covered2017–20262015–2027
Configurations on record32106

Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.

Genesis G90 vs Mercedes-Benz S-Class dimensions and size

The Mercedes-Benz S-Class is 0.4 inches longer than the Genesis G90 on a wheelbase 1.2 inches longer, and 119 lbs lighter. At over 200 inches, the larger of the two is past the comfortable limit of a standard 192-inch single garage bay once you allow walking room.

Genesis G90 versus Mercedes-Benz S-Class exterior dimensions
DimensionGenesis G90 (2026)Mercedes-Benz S-Class (2026)Difference
Length207.9 in208.3 in0.4 in
Width (excl. mirrors)58.7 in76.8 in18.1 in
Height76 in59.1 in16.9 in
Wheelbase125.2 in126.4 in1.2 in
Curb weight4,859 lbs4,740 lbs119 lbs

Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.

Genesis G90 vs Mercedes-Benz S-Class: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Mercedes-Benz S-Class burns about $2,900 of fuel annually against $3,600 for the Genesis G90. That $700 yearly gap compounds to roughly $3,500 over five years and $5,600 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the Mercedes-Benz S-Class leads in both cycles — 24 mpg city and 31 mpg highway against 18 and 26 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Genesis G90 is recorded with 3 distinct engine configurations (SIDI & PFI, SIDI & PFI; Mild Hybrid, SIDI), the Mercedes-Benz S-Class with 4 (SIDI; Mild Hybrid, 6.0, SIDI; PHEV). Across 32 recorded Genesis G90 configurations and 106 for the Mercedes-Benz S-Class, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the Genesis G90 is offered with All-Wheel Drive, Rear-Wheel Drive, the Mercedes-Benz S-Class with All-Wheel Drive, 4-Wheel Drive, Rear-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Large Cars and Large Cars respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Mercedes-Benz S-Class emits 106 g/mile of CO2 versus 426 g/mile for the Genesis G90. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.

G90 vs S-Class: common questions

Which is better on gas, the Genesis G90 or the Mercedes-Benz S-Class?

The Mercedes-Benz S-Class is the more efficient of the two: it reaches 26 mpg combined versus 21 mpg for the Genesis G90, a 5 mpg advantage and costs about $700 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Mercedes-Benz S-Class runs about $2,900 a year in fuel at its most efficient configuration, versus about $3,600 for the Genesis G90 — a difference of roughly $700 per year.

What engines do the G90 and S-Class offer?

Genesis G90: SIDI & PFI, SIDI & PFI; Mild Hybrid, SIDI. Mercedes-Benz S-Class: SIDI; Mild Hybrid, 6.0, SIDI; PHEV, SIDI.

Are they in the same vehicle class?

Yes — the EPA classifies both the Genesis G90 and the Mercedes-Benz S-Class as Large Cars, so they compete directly.

More G90 comparisons

More S-Class comparisons

Comparison id: genesis-g90-vs-mercedes-benz-s-class