Earning 24 MPG combined, the 2018 Buick LaCrosse with the 3.6L V6 isn’t chasing Prius owners, nor is it meant to. It’s a full-size sedan aimed at buyers who prioritize a smooth ride, a quiet cabin, and traditional American luxury over outright fuel efficiency. These buyers value a relaxed driving experience with ample power for highway cruising and may find the gas mileage perfectly acceptable for the vehicle’s size and mission.

City and highway performance

The EPA estimates the 2018 LaCrosse 3.6L V6 achieves 21 MPG in the city and 30 MPG on the highway. The city figure reflects the engine’s output and the car’s weight. A larger V6 needs more fuel to get a relatively hefty sedan moving from a standstill. The highway MPG is more respectable, benefitting from the engine’s ability to settle into a relaxed cruise and the nine-speed automatic transmission optimizing efficiency at higher speeds. Note that the 30 MPG figure is achievable only if you resist the urge to fully exploit the 3.6L V6’s 310 horsepower. This car invites moderate throttle inputs with a reward of smooth, effortless acceleration.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Buick LaCrosse 3.6L V6 to be precisely $1,800. This figure is based on driving 15,000 miles per year and using national average fuel prices. Keep in mind this is just an estimate, your actual fuel costs will vary depending on your driving habits, the type of driving you do (city vs. highway), and the prevailing gas prices in your area. Someone who primarily drives in stop-and-go traffic will likely exceed this estimate, while someone who sticks to long highway trips may come in a bit lower. It’s a useful benchmark but should be considered within that context.

Real-world expectations

While the EPA figures provide a standardized baseline, real-world MPG can differ based on numerous factors. Aggressive driving, frequent hard acceleration, and neglecting routine maintenance like tire inflation and air filter replacement will negatively impact fuel economy. Conversely, anticipating traffic flow, using cruise control on the highway, and ensuring proper tire pressure can help you get closer to, or even slightly exceed, the EPA estimates. Owners using premium fuel may see only marginal increases in MPG, if any, negating the cost benefit. Consult the owner’s manual for Buick’s fuel recommendation.

How it compares

The 2018 LaCrosse 3.6L V6’s MPG is in line with other large sedans from that era. For instance, the Toyota Avalon, known for its reliability, delivered around 22 MPG combined with its V6 engine. The Chrysler 300, another competitor offering similar size and comfort, hovered around 23 MPG combined with its V6. The Acura TLX offered a 290-hp V6 paired with all-wheel drive (SH-AWD) and only managed around 24 MPG combined. While smaller displacement turbocharged offerings are gaining popularity, this specific Buick is intended for those prioritizing smoothness and available power from a naturally aspirated V6 more than maximizing every last MPG. To explore all Buick fuel economy data, consider what trade-offs you are willing to make to get more MPG.

Tips to maximize efficiency

Use the LaCrosse’s cruise control, especially on long highway stretches. Maintaining a consistent speed not only reduces driver fatigue, but also minimizes unnecessary acceleration and deceleration, both of which consume extra fuel. The nine-speed automatic transmission is designed to keep the engine in its most efficient range at cruising speeds, so let it do its job.

Keep your tires properly inflated. Check the tire pressure regularly and inflate them to the recommended pressure listed on the sticker inside the driver’s side door. Underinflated tires increase rolling resistance, forcing the engine to work harder and reducing fuel economy. It’s a simple, yet effective, way to save money at the pump.

Avoid unnecessary idling. If you’re stopped for more than a minute, turn off the engine. Extended idling consumes fuel without moving the car, essentially wasting gas. Today’s starters are reliable enough to handle frequent restarts without premature wear, especially with modern hybrids.

Plan your trips strategically. Combine errands into a single trip to minimize cold starts. Cold starts are less fuel-efficient because the engine requires more fuel to reach its optimal operating temperature. Doing a little advance thought saves both time and money.

Keep up with regular maintenance. Ensure your LaCrosse receives regular oil changes, air filter replacements, and tune-ups as recommended in the owner’s manual. A well-maintained engine runs more efficiently, maximizing fuel economy and reducing the risk of costly repairs. You can learn more about LACROSSE MPG across all years on this site.