23 MPG combined is not the main selling point of a 2021 Lexus IS 350 with the 3.5L V6. People buy this car for its smooth power delivery, proven reliability, and the feeling of solidity that Lexus consistently provides. Fuel economy is a consideration, of course, but it’s less important than tactile quality, confident handling, and the quiet confidence that comes with owning a Lexus.

City and highway performance

The EPA estimates for the 2021 Lexus IS 350 are 20 MPG in the city and 28 MPG on the highway. The city figure reflects stop-and-go traffic where the 3.5L V6, while refined, needs to work harder to move this relatively heavy sedan. The 8-speed automatic transmission does its best to optimize fuel use, but the engine’s displacement and the car’s curb weight dictate the outcome. The highway figure, on the other hand, is more appealing. At a steady cruising speed, the engine operates more efficiently, showcasing the benefits of the well-engineered powertrain. Drivers who primarily commute on the open road will likely see figures close to, or even slightly above, the EPA estimate.

Annual fuel cost

The EPA estimates that the annual fuel cost for the 2021 Lexus IS 350 3.5L is $2,500. This figure is based on driving 15,000 miles per year and assumes the use of gasoline priced at the national average. Keep in mind that this is just an estimate. Your actual fuel costs will vary depending on your driving habits, local fuel prices, and the specific blend of gasoline you use. Those with a heavy foot or who frequently drive in congested urban environments will likely exceed this figure, while those who prioritize fuel efficiency and primarily drive on the highway may spend less.

Real-world expectations

While the EPA provides a standard benchmark, real-world MPG for the 2021 Lexus IS 350 will vary. Drivers who frequently use Sport mode, which alters the transmission’s shift points and throttle response, will see a drop in fuel economy. Aggressive acceleration and hard braking will also negatively impact efficiency. Conversely, a smoother, more deliberate driving style will help maximize MPG. Regularly checking tire pressure, avoiding unnecessary idling, and removing excess weight from the vehicle can also improve fuel economy. The way you drive has as much influence on MPG as the car itself. See IS MPG across all years to see how these figures have changed over time.

How it compares

In the compact luxury sedan segment, the 2021 Lexus IS 350’s fuel economy is average. The BMW 330i, for instance, achieves an EPA-estimated 28 MPG combined with its turbocharged four-cylinder engine to maximize fuel efficiency without sacrificing performance. The Mercedes-Benz C300, similarly equipped with a turbocharged four-cylinder, achieves around 25 MPG combined. The Acura TLX, with its standard 2.0L turbo, manages 25 MPG combined, but the more powerful TLX Type S drops to a much lower figure. The IS 350 sits roughly mid-pack, a trade-off buyers are willing to make for a naturally aspirated V6 engine with years of proven reliability. Drivers concerned about efficiency might find better options, but for those prioritizing Lexus’s unique characteristics, the fuel economy is an acceptable compromise. You can also check all Lexus fuel economy data for a wider perspective.

Tips to maximize efficiency

Avoid aggressive acceleration. The Lexus IS 350’s V6 is responsive, and using that power frequently saps fuel. Gentle acceleration allows the engine to operate more efficiently. Try to anticipate traffic flow, avoiding abrupt changes in speed.

Use cruise control on the highway. Maintaining a consistent speed minimizes unnecessary throttle adjustments, leading to better fuel efficiency. Modern adaptive cruise control systems can optimize efficiency by automatically adjusting speed to maintain a safe following distance.

Ensure proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and reducing fuel economy. Regularly check your tire pressure and inflate them to the recommended level, which can be found on a sticker inside the driver’s side door jamb.

Minimize idling. Modern engines consume a surprising amount of fuel when idling. If you anticipate being stationary for more than a minute, it’s generally more efficient to turn off the engine. Restarting the engine consumes less fuel than letting it idle.