Audi A8 vs Genesis G90: Specs Compared

Also searched as Genesis G90 vs Audi A8 specs — both orientations show this same side-by-side comparison.

The Audi A8 is the more efficient of the two: it reaches 28 mpg combined versus 21 mpg for the Genesis G90, a 7 mpg advantage and costs about $750 less per year to fuel.

Across 5 measured categories, the Audi A8 leads in 5. Figures are EPA test data, not manufacturer claims.

2015–2027

Audi A8

Large Cars · 28 configurations

28mpg combined (best)
All Audi A8 specs

2017–2026

Genesis G90

Large Cars · 32 configurations

21mpg combined (best)
All Genesis G90 specs

Head-to-head specifications

MetricAudi A8Genesis G90
Best combined MPG28 mpg ✓21 mpg
Best city MPG24 mpg ✓18 mpg
Best highway MPG36 mpg ✓26 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$2,850 ✓$3,600
Lowest CO2 output213 g/mi ✓426 g/mi
Engines offeredSIDI; Mild Hybrid, SIDI; PHEV, SIDI, 3.0SIDI & PFI, SIDI & PFI; Mild Hybrid, SIDI
TransmissionsAutomatic (S8)Automatic (S8)
DrivetrainsAll-Wheel Drive, 4-Wheel DriveAll-Wheel Drive, Rear-Wheel Drive
Fuel typesPremium, Premium and Electricity, DieselPremium
EPA classLarge CarsLarge Cars
Years covered2015–20272017–2026
Configurations on record2832

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

Audi A8 vs Genesis G90 dimensions and size

The Genesis G90 is 4.3 inches longer than the Audi A8 on a wheelbase 7.1 inches longer, and 460.8 lbs heavier. 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.

Audi A8 versus Genesis G90 exterior dimensions
DimensionAudi A8 (2019)Genesis G90 (2026)Difference
Length203.5 in207.9 in4.3 in
Width (excl. mirrors)76.8 in58.7 in18.1 in
Height57.9 in76 in18.1 in
Wheelbase118.1 in125.2 in7.1 in
Curb weight4,398 lbs4,859 lbs461 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.

Audi A8 vs Genesis G90: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Audi A8 burns about $2,850 of fuel annually against $3,600 for the Genesis G90. That $750 yearly gap compounds to roughly $3,750 over five years and $6,000 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 Audi A8 leads in both cycles — 24 mpg city and 36 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 Audi A8 is recorded with 4 distinct engine configurations (SIDI; Mild Hybrid, SIDI; PHEV, SIDI), the Genesis G90 with 3 (SIDI & PFI, SIDI & PFI; Mild Hybrid, SIDI). Across 28 recorded Audi A8 configurations and 32 for the Genesis G90, 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 Audi A8 is offered with All-Wheel Drive, 4-Wheel Drive, the Genesis G90 with All-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 Audi A8 emits 213 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.

A8 vs G90: common questions

Which is better on gas, the Audi A8 or the Genesis G90?

The Audi A8 is the more efficient of the two: it reaches 28 mpg combined versus 21 mpg for the Genesis G90, a 7 mpg advantage and costs about $750 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the Audi A8 runs about $2,850 a year in fuel at its most efficient configuration, versus about $3,600 for the Genesis G90 — a difference of roughly $750 per year.

What engines do the A8 and G90 offer?

Audi A8: SIDI; Mild Hybrid, SIDI; PHEV, SIDI, 3.0. Genesis G90: SIDI & PFI, SIDI & PFI; Mild Hybrid, SIDI.

Are they in the same vehicle class?

Yes — the EPA classifies both the Audi A8 and the Genesis G90 as Large Cars, so they compete directly.

More A8 comparisons

More G90 comparisons

Comparison id: audi-a8-vs-genesis-g90