| Engine | 3.5L 6-cyl |
| Transmission | Automatic (S8) |
| Drive | Rear-Wheel Drive |
| Fuel Type | Premium Gasoline |
| Vehicle Class | Midsize Cars |
| Engine Desc | SIDI & PFI |
| Start-Stop | No |
| EPA Vehicle ID | 42128 |
The 2020 Lexus GS 350’s 23 MPG combined fuel economy won’t win any awards, but it likely won’t deter its target buyer either. This car is purchased for its smooth power delivery, refined ride, and unwavering reliability, not for its ability to conserve fuel. The GS 350 suits those who value traditional luxury sedan qualities over the latest tech or hybrid powertrains. It’s a comfortable and capable machine, and its fuel consumption reflects that.
City and highway performance
The EPA estimates the 2020 Lexus GS 350 at 20 MPG in the city and 28 MPG on the highway. This split is typical for a naturally aspirated V6 engine paired with a conventional automatic transmission. The city figure reflects the engine’s need to work harder in stop-and-go traffic. The highway number shows the benefits of cruising at a steady speed with the transmission in its higher gears. The rear-wheel-drive and all-wheel-drive versions of the GS 350 share these EPA estimates, proving the added traction doesn’t reduce fuel economy in government testing.
Annual fuel cost
The EPA says the 2020 Lexus GS 350 will cost you approximately $2,500 in fuel annually. That figure is based on driving 15,000 miles per year, with a mix of 55% city and 45% highway driving. The calculation also assumes a national average fuel price. Your actual fuel costs could be higher or lower depending on your driving habits and local fuel prices. Someone who primarily drives in congested city traffic will likely exceed the $2,500 estimate, while someone who mostly drives long highway trips might spend less. It’s a benchmark, not a guarantee. Remember to consult all Lexus fuel economy data if you’re cross-shopping trims.
Real-world expectations
While the EPA provides a standardized measure of fuel economy, real-world results can vary. The GS 350’s 3.5L V6 is smooth and responsive and likes to be revved. Drivers who appreciate the engine’s power and aren’t shy with the throttle will likely see numbers closer to the low end of the EPA range, or even slightly below. But those who prioritize a gentle driving style and maximize the use of cruise control on the highway could potentially achieve slightly better than the EPA estimates. Factors such as tire pressure, vehicle maintenance, and the weather can also influence fuel consumption. Consider joining online owner forums for the GS MPG across all years to compare notes and see what other drivers are experiencing.
How it compares
In the mid-size luxury sedan segment, the GS 350’s fuel economy is average. The BMW 540i, with its turbocharged inline-six, achieves a slightly better 25 MPG combined. The Mercedes-Benz E 450, also with a turbocharged six-cylinder, offers a similar 24 MPG combined. However, the GS 350 outperforms rivals like the Genesis G80 3.5T, which gets around 20 MPG combined with its twin-turbo V6. The Acura TLX, in its V6 SH-AWD configuration, also matches the GS 350’s 23 MPG combined rating but gets better numbers on the highway because of its transmission. These comparisons matter because buyers in this segment are often weighing performance, luxury, and running costs, and every MPG counts.
Tips to maximize efficiency
The GS 350 doesn’t feature fuel-saving technologies like stop-start, so smooth driving is important. Avoid aggressive acceleration and braking, anticipating traffic flow to maintain a consistent speed. The 8-speed automatic transmission is programmed for efficiency, so let it do its job without constantly overriding it with manual shifts unless it’s truly necessary.
Ensure your tires are properly inflated to the recommended pressure indicated on the driver’s side doorjamb. Underinflated tires increase rolling resistance, which directly impacts fuel economy. Check your tire pressures regularly, especially during seasonal temperature changes.
Regular maintenance is critical for fuel efficiency. Keep the engine properly tuned, and ensure that the air filter is clean. A clogged air filter restricts airflow to the engine, forcing it to work harder and consume more fuel.
Minimize idling as much as possible. Letting the engine run while stationary burns fuel unnecessarily. If you’re stopped for more than a minute or two, turn off the engine. While the GS 350 does not have automatic stop/start, you can still save fuel with conscious effort.
Consider using a fuel additive designed to clean fuel injectors. Clogged injectors can disrupt the fuel spray pattern, leading to incomplete combustion and reduced fuel economy. A quality fuel additive can help keep the fuel system clean and operating efficiently.