22 MPG combined is what you can expect from the 2024 Lexus IS 300 AWD with its naturally aspirated 3.5L V6. It’s a number that won’t win any efficiency awards, but it’s also a known quantity for the specific buyer this car attracts: Someone prioritizing a smooth, reliable powertrain and a badge of proven luxury over saving money on gas. They understand the trade-off between old-school charm and modern efficiency, and they’re making a conscious choice.

City and highway performance

The EPA estimates 19 MPG in the city and 26 MPG on the highway for this all-wheel-drive IS 300. The city figure reflects the engine’s need to work harder in stop-and-go traffic, where its relatively large displacement hampers fuel consumption. On the open road, however, the 26 MPG shows that the V6 can cruise comfortably, although its older six-speed automatic transmission is less efficient than the 8- and 10-speed units found in some competitors. This lower highway figure also reflects the drag of the all-wheel-drive system, as the rear-wheel-drive IS 300 will return better numbers.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2024 Lexus IS 300 AWD is $2,650. This figure is based on driving 15,000 miles per year and using national average fuel prices. Keep in mind that this is an estimate, and your actual fuel costs may vary depending on your driving habits, local fuel prices, and the type of fuel you use. Premium fuel is recommended for optimal performance in this engine but it is possible to run regular fuel, which would impact this cost positively.

Real-world expectations

While the EPA provides a standardized testing method, real-world MPG can differ based on driving style, traffic conditions, and even tire pressure. Aggressive acceleration, frequent short trips, and prolonged idling will all negatively impact fuel economy. However, with mindful driving, it’s possible to get close to the EPA’s estimates. Owners reporting on forums often see numbers within 1-2 MPG of the official figures, suggesting the EPA’s testing is reasonably representative of typical driving conditions for this specific vehicle. See IS MPG across all years.

How it compares

The IS 300 AWD’s fuel economy lags behind some of its key competitors. The BMW 330i xDrive, for example, manages a combined 28 MPG thanks to its turbocharged four-cylinder engine. Similarly, the Mercedes-Benz C 300 4MATIC achieves a combined 27 MPG, showing the efficiency gains possible with smaller, forced-induction engines. Even Acura’s TLX, with its turbocharged four-cylinder, boasts a combined 25 MPG. The Lexus is at the bottom of the barrel here. However, Lexus loyalists might shrug at these numbers; they prioritize the V6 engine’s proven reliability and linear power delivery over the potential fuel savings offered by the competition. People looking for all Lexus fuel economy data may also want to shop different Lexus vehicle models.

Tips to maximize efficiency

Avoid aggressive acceleration. The IS 300’s V6 responds well to a gentle foot, and easing into the throttle will significantly reduce fuel consumption, especially in city driving. The linear power delivery of the V6 makes it easy to drive smoothly, something that owners should try to take advantage of.

Maintain proper tire pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. Check your tire pressure regularly and inflate them to the recommended levels, which can be found on a sticker inside the driver’s side doorjamb.

Minimize idling. Letting the engine idle for extended periods wastes fuel. If you’re stopped for more than a minute or two, turn off the engine. Modern car engines don’t need to “warm up” before driving away; gentle driving is all that’s required. The IS 300’s strong starter motor can handle frequent restarts without issue.

Use cruise control on the highway. Maintaining a consistent speed helps optimize fuel economy. Cruise control modulates the throttle more efficiently than most drivers, especially on long highway journeys. Using cruise control will reduce the chance of sudden speed fluctuations that hurt fuel economy.