23 MPG combined won’t lead the fuel economy charts, but it’s likely not the primary consideration for buyers of the 2024 Lexus IS 350. People buy this car for its blend of understated luxury, engaging driving dynamics (especially with the rear-wheel-drive configuration), and the brand’s reputation for reliability. Fuel efficiency is secondary to the smooth, naturally aspirated V6 engine that delivers satisfying power.

City and highway performance

The EPA estimates 20 MPG in the city and 28 MPG on the highway. The city figure mirrors the IS 350’s engine working harder in stop-and-go traffic, where its responsive throttle can become a bit of a drawback if you’re trying to conserve fuel. Achieving 28 MPG highway requires a conscious effort to maintain a steady speed and resist the urge to tap into the engine’s power for passing. The eight-speed automatic transmission helps optimize fuel economy, but the relatively high-revving nature of the 3.5-liter V6 means it’s always ready to deliver performance, often at the expense of efficiency. It’s a trade-off the IS 350 buyer accepts.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 Lexus IS 350 at $2,500. This figure is based on driving 15,000 miles per year and using national average fuel prices. Your actual fuel costs may vary significantly depending on your driving habits, the type of driving you do, and gasoline prices in your area. If you primarily drive in the city, you’ll likely exceed this estimate. Similarly, spirited driving will also increase that number. The IS 350 requires premium fuel, further contributing to its overall running costs. You can find all Lexus fuel economy data on our site.

Real-world expectations

While the EPA numbers provide a useful baseline, real-world fuel economy for the IS 350 can vary considerably. Drivers who frequently use the V6’s power can expect to see numbers closer to the low end of the EPA range and perhaps even dipping below 20 MPG in mixed driving. More relaxed drivers who prioritize smooth acceleration and consistent speeds may achieve figures closer to the EPA combined estimate, and possibly even exceed the 28 MPG highway rating on long road trips. However, consistently achieving or surpassing the EPA numbers requires mindful driving habits.

How it compares

The IS 350’s fuel economy is in the middle of its competitive set. The BMW 330i, with its turbocharged four-cylinder engine, manages a combined 28 MPG. The Mercedes-Benz C300, also featuring a turbocharged four-cylinder, achieves a similar 28 MPG combined rating. These cars deliver their power differently compared to the Lexus and lack the same engine sound as the Lexus V6. The Acura TLX, when equipped with its four-cylinder engine, achieves a respectable 25 MPG combined, but when equipped with the Type S trim’s V6, the MPG drops to 21 combined. For many IS 350 buyers, trading a few MPG for the Lexus’s driving experience and reputation for reliability is an easy decision. You can compare IS MPG across all years on our site.

Tips to maximize efficiency

Avoid aggressive acceleration. The IS 350’s V6 engine is responsive, but each burst of power consumes more fuel. Gently accelerating and maintaining a steady pace will improve your fuel economy.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressure regularly and inflate them to the recommended levels listed on the driver’s side doorjamb.

Reduce unnecessary weight. Remove any unnecessary items from your trunk and passenger compartment. Extra weight requires more energy to accelerate and maintain speed, impacting fuel efficiency.

Plan your routes strategically. Minimize stop-and-go driving whenever possible. Idling consumes fuel without covering any distance. Opt for routes with fewer traffic lights and smoother traffic flow.

Use cruise control on the highway. Maintaining a consistent speed with cruise control minimizes fluctuations in throttle input, which can improve fuel economy on long highway drives.