20 MPG combined makes the 2025 Genesis G90 MHEV 3.5L 6-cyl a luxury sedan that prioritizes supreme comfort, effortless power delivery, and an impeccably refined cabin over raw fuel efficiency. This isn’t a vehicle purchased to pinch pennies at the pump; it’s chosen by individuals who appreciate meticulous craftsmanship, quiet operation, and a driving experience that insulates them from the outside world. The G90 exists as a statement of understated elegance and technological features, a clear contender in the top tier of executive sedans. Its 20 MPG figure is simply a cost of admission for a genuinely world-class experience, a number that slots squarely into the expectations of its clientele.

City and highway performance

Looking closer at the EPA figures, the 2025 Genesis G90 MHEV 3.5L 6-cyl gets 17 MPG in city driving and 24 MPG on the highway. These numbers align with the G90’s character. In city environments, where the 3.5-liter twin-turbo V6 and its 48V mild-hybrid system are frequently accelerating from standstill, idling, and navigating stop-and-go traffic, the 17 MPG reflects the demands placed on a substantial, powerful vehicle. This is not a commuter car, it’s a quiet sanctuary. Highway cruising, by contrast, allows the 8-speed automatic transmission to settle into its taller gears, letting the engine hum along efficiently and achieving a more respectable 24 MPG. For the G90 owner, long journeys are meant to be traversed in ultimate comfort, and the smooth, composed highway performance, rather than an ultra-high MPG figure, is the primary consideration. The mild-hybrid system, while contributing to overall efficiency, plays a more pronounced role in smoothing power delivery and enhancing the start-stop system than in providing significant electric-only range.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,900 for the 2025 Genesis G90 MHEV 3.5L 6-cyl. This figure is derived using a standardized calculation based on driving 15,000 miles per year, split between city and highway driving, and using national average fuel prices. For a vehicle of the G90’s caliber and price point, this annual fuel expenditure is well within the acceptable range for its target demographic. Buyers of the G90 are not typically monitoring fuel costs as a primary purchasing factor. Instead, they weigh the overall ownership experience, including service, depreciation, and the sheer pleasure of driving (or being driven in) such a luxurious machine. The $2,900 simply represents one slice of the holistic financial picture for a premium executive sedan.

Real-world expectations

In real-world driving, owners of the 2025 Genesis G90 MHEV 3.5L 6-cyl can expect its fuel economy to hover very close to the EPA estimates. The mild-hybrid system is subtle, primarily aiding in torque fill and making the automatic start/stop function exceptionally smooth, almost imperceptible. This contributes to the overall refined driving experience rather than providing significant boosts in MPG. Aggressive driving, frequent short trips, or heavy use of accessories will push the numbers closer to the city estimate of 17 MPG. Conversely, extended highway cruises with a light foot will allow the G90 to approach or even slightly exceed its 24 MPG highway rating. The G90’s mission is uncompromised luxury and performance, and its fuel consumption naturally aligns with that mission. Those who choose the G90 understand they are investing in a vehicle designed for quiet and strong power, not ultimate economy. The twin-turbo V6 is designed for smooth, effortless acceleration, and owners will appreciate this characteristic far more than minor fluctuations in fuel consumption. For more information on all Genesis fuel economy data, you can explore our database.

How it compares

The 2025 Genesis G90 MHEV 3.5L 6-cyl competes directly with established players in the full-size luxury sedan segment, and its 20 MPG combined figure is quite competitive within this exclusive club. Consider the Mercedes-Benz S-Class S500 4MATIC Sedan, which, with its 3.0L inline-6 mild-hybrid powertrain, achieves 23 MPG combined (20 city/28 highway). Here, the S500 edges out the G90 on efficiency, largely due to its smaller displacement engine, although both offer formidable power. The BMW 740i, similarly equipped with a 3.0L mild-hybrid inline-6, hits 27 MPG combined (25 city/31 highway), representing a more pronounced efficiency advantage. However, these comparisons are rarely decided on MPG alone, buyer loyalty, brand prestige, interior design ethos, and specific driving dynamics often carry more weight. For example, a buyer might prefer the G90’s unique cabin aesthetic or its slightly softer, more isolating ride quality over the marginal fuel cost savings offered by a competitor. Another key competitor is the Audi A8, though in its current generation, the primary powertrain is a 3.0L V6. The G90 carves out its niche by offering a distinct blend of Korean luxury, a reliable twin-turbo V6, and a compelling value relative to its peers. For detailed information on G90 MPG across all years, we have extensive data available.

Tips to maximize efficiency

While fuel economy isn’t the G90’s primary selling point, owners can certainly employ strategies to optimize their mileage. Smooth acceleration and braking, avoiding sudden inputs, will allow the 8-speed automatic to operate efficiently and prevent the twin-turbo V6 from working harder than necessary. This also enhances the G90’s already smooth driving dynamics.

Regular maintenance is important for any vehicle, especially a mild-hybrid like the G90. Adhering to the factory-recommended service schedule, including oil changes and tire rotations, ensures all vehicle systems are operating at peak efficiency, which directly impacts fuel consumption.

Maintaining proper tire inflation pressure is a simple yet effective way to improve fuel economy. Underinflated tires increase rolling resistance, forcing the engine to expend more energy to move the vehicle. Check your tire pressures regularly, especially before long trips.

Strategic use of the G90’s drive modes can also make a difference. While Eco mode might seem counter to the G90’s character, it can slightly alter throttle response and transmission shift points to prioritize efficiency during routine commutes or in heavy traffic, without significantly compromising comfort.

Reducing unnecessary weight in the trunk or cabin can also contribute to marginal efficiency gains. While the G90 is a heavy vehicle, shedding any extraneous items will lessen the load on the engine and transmission, leading to slightly improved fuel economy over time.