23 MPG combined isn’t going to win any awards in 2019, but for the Lexus IS 350 with its smooth 3.5L V6, it’s a perfectly acceptable trade-off for the engaging driving experience. This isn’t a car bought by hypermilers or those intensely focused on lower fuel costs. Buyers choose the IS 350 for its blend of rear-wheel-drive (or all-wheel-drive) athleticism, Lexus refinement, and a healthy dose of naturally aspirated power. Fuel economy, while a consideration, usually ranks below driver enjoyment on the priority list.

City and highway performance

The EPA estimates for the IS 350 are 20 MPG in the city and 28 MPG on the highway. The city figure reflects the realities of stop-and-go driving where the engine is constantly accelerating and decelerating, conditions that don’t favor efficiency, especially with a conventional automatic transmission. The 28 MPG highway figure is more respectable, indicating decent efficiency during steady-state cruising. However, achieving this number requires a disciplined right foot; aggressive acceleration and higher speeds will significantly reduce highway MPG. The eight-speed automatic transmission (S8) does its part to optimize fuel economy, but ultimately, the driver’s behavior has a major impact.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2019 Lexus IS 350 at $2,500. This figure is based on driving 15,000 miles per year, with a mix of city and highway driving, using the EPA’s fuel economy estimates and the national average fuel price for premium unleaded gasoline (which the IS 350 requires). Your actual fuel costs may vary depending on your driving habits, the type of driving you do (primarily city vs. highway), and the prevailing gas prices in your area. Drivers who cover more than 15,000 miles annually or frequently encounter heavy traffic can expect to exceed this $2,500 estimate. The EPA provides all Lexus fuel economy data for comparison to other models.

Real-world expectations

While the EPA estimates provide a useful baseline, real-world MPG often deviates. IS 350 owners often report slightly lower combined MPG than the official 23 MPG figure, particularly in areas with heavy traffic or hilly terrain. Expect combined MPG to hover closer to 20-22 MPG if you drive mostly in the city. Highway MPG is more likely to align with the EPA’s 28 MPG, provided you maintain a reasonable speed and avoid frequent bursts of acceleration. Ultimately, individual driving styles and local conditions play a significant role in determining actual fuel consumption. Consult the IS MPG across all years for more real-world estimates.

How it compares

Compared to its competitors, the 2019 Lexus IS 350 lands somewhere in the middle of the pack in terms of fuel economy. The BMW 330i, with its turbocharged 2.0L four-cylinder, manages a significantly better 28 MPG combined. The Mercedes-Benz C300, also equipped with a turbocharged 2.0L, achieves nearly identical fuel economy to the BMW. However, neither offers the smooth, naturally aspirated power delivery of the IS 350’s V6, which is a key differentiator for many buyers. The Infiniti Q50 with its 3.0t engine comes closer in terms of power, but its fuel economy is similar to the Lexus. The Acura TLX, particularly with the V6, also competes in this space, offering a slightly more economical powertrain but foregoing the rear-wheel drive focus of the IS. Buyers cross-shopping these cars prioritize different aspects; those favoring efficiency will likely gravitate towards the BMW or Mercedes, while those wanting more character and power may prefer the Lexus or Infiniti. The IS 350’s fuel economy is accepted as a known quantity, a compromise for the driving experience it delivers.

Tips to maximize efficiency

Gentle acceleration is key to improving fuel economy in the IS 350. The V6 engine is responsive, but each time you rapidly accelerate, you are dumping fuel into the engine. Anticipate traffic flow and accelerate smoothly, allowing the transmission to upshift efficiently.

Maintain a steady speed on the highway, avoiding excessive speeding and abrupt lane changes. Using cruise control can help you maintain a consistent speed and reduce fuel consumption. Even small variations in speed can significantly impact fuel economy at highway speeds.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, which forces the engine to work harder and consumes more fuel. Check your tire pressure regularly and inflate them to the recommended level specified on the doorjamb.

Avoid unnecessary idling. If you’re stopped for more than a minute, turn off the engine. Modern cars restart quickly and easily, and avoiding idling can save a surprising amount of fuel, especially in city driving.

Reduce excess weight in the vehicle. The heavier your car, the more fuel it consumes. Remove any unnecessary items from the trunk and back seats to lighten the load and improve fuel efficiency.