2025 Infiniti QX80 Fuel Economy Real-World Test: Turbocharged V6 vs. The Old V8
Thereโs a moment when youโre filling up a massive luxury SUV and watching the dollars tick past $100โand you start wondering if that new twin-turbo V6 is actually saving you anything at the pump.
The 2025 Infiniti QX80 made a bold move. It ditched the old 5.6-liter V8 for a brand-new 3.5-liter twin-turbocharged V6โthe VR35DDTT. The promises were big: more power, more torque, and better fuel economy. But does the real world deliver?
Letโs look at the numbers, compare the old V8 to the new turbo V6, and figure out what youโll actually see at the pump.
TL;DR
The new 2025 QX80โs twin-turbo V6 is slightly more fuel-efficient than the old V8, but the improvement is modestโnot a game-changer. EPA ratings show a gain of about 1-2 MPG combined: the old V8 got 14 city / 20 highway for RWD models, while the new 2WD gets 16 city / 20 highway and the 4WD gets 16 city / 19 highway. Real-world testing of the 4WD Autograph returned just 15.9 MPG. The new engine also requires premium fuel, so the savings at the pump are minimal. The real win is the extra 50 horsepower and massive 103 lb-ft of torqueโnot the fuel economy.
The Official Numbers: EPA Ratings
Hereโs what the EPA says about the 2025 QX80:
| Model | City MPG | Highway MPG | Combined MPG |
|---|---|---|---|
| 2025 QX80 2WD (new V6) | 16 | 20 | 18 |
| 2025 QX80 4WD (new V6) | 16 | 19 | 17 |
For comparison, the 2024 QX80 with the 5.6L V8 (RWD) was rated at 14 city / 20 highway. The 2020 model had similar ratings: 14/20 MPG.
The bottom line: The new V6 saves you about 1-2 MPG in the city and is about the same on the highway. Thatโs an improvement, but itโs not a revolution.
Real-World Test: What Owners Are Seeing
Official numbers are one thing. Real-world driving is another.
Consumer Guide tested a 2025 QX80 Autograph 4X4 over 109 miles with a 70% city / 30% highway driving mix. They recorded 15.9 MPG. Thatโs below the EPAโs 17 MPG combined estimate for the 4WD model.
This is pretty typical for large, heavy SUVsโespecially when most of your driving is in the city. The stop-and-go nature of urban driving hurts fuel economy, and the QX80 weighs over 5,600 pounds.
The Old V8 vs. The New V6: The Full Picture
Letโs stack them side by side:
| Spec | 2024 QX80 (V8) | 2025 QX80 (V6) |
|---|---|---|
| Engine | 5.6L V8 | 3.5L twin-turbo V6 |
| Horsepower | 400 hp | 450 hp |
| Torque | 413 lb-ft | 516 lb-ft |
| Transmission | 7-speed auto | 9-speed auto |
| Fuel Economy (combined) | ~14-16 MPG | ~17-18 MPG |
The new engine delivers:
- +50 horsepower
- +103 lb-ft of torque (the highest in Infiniti history)
- Better low-end response (90% of peak torque available by 2,000 RPM)
- Slightly better fuel economy (about 10% improvement according to Infiniti)
But thereโs a catch: the improvement in fuel economy is modest because the QX80 is still a massive, heavy SUV. The 9-speed transmission helps, but physics is physics.
Why the Fuel Economy Isnโt Better
Hereโs the thing about turbocharged engines: theyโre more efficient if you stay out of the boost. But the QX80 is a 6,000-pound full-size SUV. To move that much weight, the turbos are spooling regularly. Youโre not getting V6 fuel economy in a truck that sizeโyouโre getting V8-like fuel economy with slightly better numbers.
Infiniti claims the new powertrain improves combined fuel economy by about 14-28% over the old V8. But the EPA numbers tell a different storyโa modest 1-2 MPG gain. Why the difference? The old V8 was also thirsty, and the new one still has to work hard to move a heavy vehicle.
Is the Upgrade Worth It?
If youโre buying the 2025 QX80 primarily to save money on gas, youโll be disappointed. The improvement is real but small. You wonโt see a dramatic difference at the pump.
But hereโs what you do get:
- Significantly more power: 450 hp is a huge jump from 400.
- Massive torque: 516 lb-ft makes towing and merging effortless.
- Smoother transmission: The 9-speed is more responsive.
- Better acceleration: 0-60 times drop from around 6.5 seconds to the mid-5-second range.
The fuel economy is a nice bonus, but the real win is performance. Youโre getting a more powerful, more refined SUV that happens to be slightly more efficient.
Frequently Asked Questions
What is the fuel economy of the 2025 Infiniti QX80?
The 2WD model is rated at 16 MPG city / 20 MPG highway / 18 combined. The 4WD model is rated at 16 city / 19 highway / 17 combined.
Is the 2025 QX80 more fuel-efficient than the old V8?
Yes, by about 1-2 MPG combined. The old V8 was rated at 14-16 MPG combined, while the new V6 gets 17-18 MPG.
What is the real-world fuel economy of the 2025 QX80?
Real-world testing of a 4WD model returned 15.9 MPG in mixed driving, below the EPA estimate of 17 MPG.
Does the 2025 QX80 require premium fuel?
Yes, both the new V6 and the old V8 require premium gasoline.
How much horsepower does the 2025 QX80 have?
The 2025 QX80 produces 450 horsepower and 516 lb-ft of torque from its new 3.5L twin-turbo V6.
What transmission does the 2025 QX80 use?
It uses a 9-speed automatic transmission, replacing the old 7-speed.
Why didnโt the fuel economy improve more?
The QX80 is a heavy, full-size SUV. Turbocharging helps efficiency, but the vehicleโs weight and aerodynamics limit how much fuel economy can improve.
References:
- FuelEconomy.gov – 2025 QX80 MPG
- INFINITI USA – 2025 QX80 Performance
- Consumer Guide – 2025 QX80 Real-World Test
- CarBuzz – 2024 QX80 MPG
- ็พๅบฆ็พ็ง – VR35DDTT Engine Specs
- Edmunds – 2020 QX80 Specs
Whatโs your takeโdoes the new V6โs performance outweigh the modest fuel savings, or do you miss the old V8โs simplicity? Drop a comment below and share your thoughts!
