21 MPG combined isn’t going to win any awards in the compact luxury sedan segment, but for the 2015 Lexus IS 350 AWD, it’s a well-understood and accepted trade-off. Those choosing this configuration, the all-wheel-drive IS 350 with its potent 3.5L V6, are prioritizing confident all-weather performance and a smooth, responsive driving experience over outright fuel efficiency. They are willingly sacrificing a few MPG for the added security and power that this model provides.

City and highway performance

The EPA estimates for the 2015 Lexus IS 350 AWD break down to 19 MPG in the city and 26 MPG on the highway. The city figure reflects the reality of stop-and-go driving, where the engine spends more time idling and accelerating from a standstill, both fuel-intensive activities. On the open road, the IS 350’s six-speed automatic transmission allows the engine to settle into a more relaxed cruising speed, leading to the improved highway figure. While 26 MPG is respectable for a V6-powered all-wheel-drive car of this era, it falls short of some competitors who were prioritizing fuel efficiency even then.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2015 Lexus IS 350 AWD is $2,750. This figure is based on driving 15,000 miles per year and using national average fuel prices. Of course, actual fuel costs will vary depending on individual driving habits, local fuel prices, and the specific type of fuel used. While some owners might consider this cost a significant factor, many choose the IS 350 AWD knowing it demands a premium at the pump, a price they are willing to pay for the car’s performance and all-weather capability.

Real-world expectations

While the EPA provides a standardized benchmark, real-world MPG can differ significantly based on driving style and conditions. Aggressive acceleration, frequent hard braking, and prolonged idling will all negatively impact fuel economy. Conversely, smooth, consistent driving at moderate speeds can help drivers approach or even exceed the EPA estimates. Also, keep in mind that winter driving, especially in areas with snow and ice, typically results in lower MPG due to cold starts, increased rolling resistance from winter tires, and the use of all-wheel-drive in slippery conditions.

How it compares

In 2015, the Lexus IS 350 AWD faced stiff competition in the compact luxury sedan segment, and fuel economy was a key battleground. The BMW 328i xDrive, for instance, with its turbocharged four-cylinder engine, boasted a combined EPA rating of 26 MPG, a noticeable advantage over the Lexus. Even the six-cylinder BMW 335i xDrive edged out the IS 350 AWD at 23 MPG combined. Similarly, the Audi A4 2.0T Quattro achieved 26 MPG combined, showcasing the efficiency benefits of turbocharging and smaller displacement engines. Choosing between these models often came down to a trade-off between Lexus’s smooth V6 power delivery and the better fuel economy of its competitors. Across the entire lineup, you can review all Lexus fuel economy data to see how the IS 350 AWD fits within the broader Lexus product family. For specifics on this car across model years, you can also review IS MPG across all years.

Tips to maximize efficiency

One of the most effective ways to improve fuel economy in the 2015 Lexus IS 350 AWD is to adopt a smoother driving style. Avoid aggressive acceleration and hard braking, anticipate traffic flow and maintain a consistent speed whenever possible. The IS 350’s responsive powertrain can encourage spirited driving, but a more gentle approach will yield noticeable improvements at the pump.

Regular maintenance is critical for optimizing fuel efficiency. Ensure that your IS 350’s tires are properly inflated, as underinflated tires increase rolling resistance and decrease MPG. Also, keep up with scheduled oil changes and air filter replacements, as these simple tasks can have a surprisingly positive impact on fuel consumption.

Minimize idling, especially during cold starts. The IS 350, like most modern vehicles, warms up relatively quickly while driving, so prolonged idling is unnecessary and wastes fuel. If you know you’ll be stopped for more than a minute or two, it’s generally more efficient to turn off the engine.

Consider using the “Eco” driving mode, if your IS 350 is equipped with it. This mode adjusts the throttle response and transmission shift points to prioritize fuel efficiency over outright performance. While it might slightly reduce the car’s responsiveness, it can help drivers achieve meaningful MPG gains, especially in city driving.