23 MPG combined will not help the 2020 Lexus IS 350 win any fuel efficiency awards, but judging this car solely on its gas mileage misses the point. This is a compact luxury sport sedan designed for driving enjoyment, a vehicle where the character of the engine and the responsiveness of the chassis are more important than squeezing every last mile out of a gallon of premium fuel. For those seeking the classic Lexus combination of reliability and refinement with a dose of sporting intent, the IS 350 remains a good choice, even if it lags behind some competitors in fuel economy.

City and highway performance

The EPA estimates for the 2020 Lexus IS 350 are 20 MPG in the city and 28 MPG on the highway. The city figure reflects stop-and-go driving, where the 3.5L V6, while smooth and eager, is less efficient than smaller, turbocharged engines found in some rivals. The highway number is more respectable, offering decent range for longer journeys. The eight-speed automatic transmission helps keep the engine in its sweet spot, but the focus is on delivering immediate power rather than maximizing efficiency at cruising speeds. Drivers who prioritize a responsive throttle and the pleasing sounds of a naturally aspirated V6 will likely find the trade-off acceptable, while those focused on fuel savings might consider other options.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2020 Lexus IS 350 is $2,500. This estimate is based on driving 15,000 miles per year and using national average fuel prices for premium gasoline, which is recommended for optimal performance in the IS 350. It assumes a fairly even mix of city and highway driving. Your actual fuel costs will vary depending on your driving habits, the type of roads you frequent, and local fuel prices. Aggressive driving, extended idling, and consistent short trips will all negatively impact your fuel economy, potentially increasing your annual spending at the pump.

Real-world expectations

While the EPA provides a standardized estimate, real-world fuel economy often differs, and many IS 350 owners report slightly lower figures, particularly in city driving. If your commute involves heavy traffic and frequent acceleration, expect to see numbers closer to the high teens. On longer highway drives, achieving or slightly exceeding the EPA’s 28 MPG is possible with careful driving. Several factors influence your personal MPG, including tire pressure, vehicle maintenance, and cargo weight. The IS 350’s sporty character encourages spirited driving, which will inevitably affect fuel efficiency, because this car rewards the driver at the expense of optimal gas mileage.

How it compares

The Lexus IS 350’s fuel economy places it in the middle of its class. For example, the BMW 330i often achieves a combined MPG of around 28, a significant advantage because of its turbocharged four-cylinder engine. Similarly, the Audi A4 45 TFSI also boasts a combined MPG in the mid-20s, outperforming the IS 350. However, both rely on forced induction. The Acura TLX, particularly with the available V6 engine, offers similar performance to the IS 350 but with comparable or slightly worse fuel economy, around 24 MPG combined. This comparison matters because buyers in this segment are often weighing performance against efficiency. The Lexus client is often willing to concede a few MPG for the smooth, linear power delivery of a naturally aspirated V6 and the reliable reputation Lexus is known for. You can see IS MPG across all years on our site for more context.

Tips to maximize efficiency

One of the simplest ways to improve your IS 350’s fuel economy is to monitor your tire pressure regularly. Underinflated tires create more rolling resistance, forcing the engine to work harder and consume more fuel. Check your tires at least once a month and inflate them to the recommended pressure listed on the driver’s side door jamb.

Avoid aggressive driving habits such as rapid acceleration and hard braking. These actions put unnecessary strain on the engine and transmission, leading to increased fuel consumption. Smooth, gradual acceleration and anticipating traffic conditions can significantly improve your mileage. Using the IS 350’s Eco mode can also temper throttle response and shift patterns in favor of efficiency, though it’s not ideal for spirited driving.

Regular maintenance is critical for good fuel economy. Ensure that your IS 350 receives scheduled servicing, including oil changes, air filter replacements, and spark plug inspections. A well-maintained engine runs more efficiently and burns fuel cleaner.

Minimize idling time whenever possible. Idling consumes fuel without covering any distance. If you anticipate sitting for more than a minute or two, turn off the engine. Modern engines are designed to restart quickly and efficiently, so you won’t cause any undue wear and tear.

Consider using cruise control on the highway. Maintaining a consistent speed helps optimize fuel consumption. By minimizing fluctuations in throttle position, cruise control can help improve highway fuel economy. Check all Lexus fuel economy data on our site.