The 2016 Mercedes-Benz SLK300 manages 27 MPG combined. While fuel efficiency isn’t the primary reason to buy a retractable-hardtop roadster, this figure prevents the SLK300 from being excessively thirsty, a reasonable tradeoff because it prioritizes open-air enjoyment and stylish looks over pure gas mileage.

City and highway performance

The EPA estimates the SLK300 at 24 MPG in the city and 32 MPG on the highway. These numbers reflect the SLK300’s dual nature: nimble around town and comfortable on longer cruises. The 2.0L turbocharged four-cylinder engine provides enough power for quick acceleration, while the nine-speed automatic transmission helps keep the engine at its best for gas mileage at higher speeds. This wide range of ratios allows for relaxed highway driving, contributing to the respectable 32 MPG figure when driven carefully. The city rating mirrors the stop-and-go of city driving, where the engine idles more or operates at lower speeds which use more gas.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2016 Mercedes-Benz SLK300 at $2,150 per year. This is based on driving 15,000 miles annually, using a mix of city and highway driving, and factoring in national average fuel prices. While individual fuel costs will vary depending on driving and local fuel prices, this gives a benchmark for comparing the SLK300’s running costs against other vehicles. For the typical SLK300 owner, who uses the car as a weekend toy or commuter, the $2,150 annual fuel cost is manageable, overshadowed by the pleasures of open-top motoring and the prestige of the Mercedes-Benz badge. You can research SLK300 MPG across all years for more information.

Real-world expectations

While the EPA estimates provide a baseline, real-world fuel economy can vary based on driving, traffic, and weather. Drivers who accelerate quickly will likely see lower fuel economy than those who accelerate smoothly and drive at consistent speeds. Similarly, driving in congested city environments will likely result in lower MPG figures than driving on open highways. The SLK300’s fuel-saving technologies, such as its engine start/stop system and efficient transmission, can help to reduce these effects and keep gas consumption reasonable. Most SLK300 drivers will achieve figures close to the EPA estimates, maybe slightly lower in tough conditions, but potentially more on relaxed highway trips.

How it compares

The 2016 Mercedes-Benz SLK300’s fuel economy is competitive among roadsters. The BMW Z4 sDrive28i achieved an EPA-estimated 26 MPG combined using a 2.0L turbocharged engine and automatic transmission. The Audi TT Roadster reached roughly 26 MPG combined with its 2.0L turbo. These roadsters prioritize driving enjoyment over ultimate efficiency, so the SLK300’s 27 MPG is good for this class, and the slight advantage over some can help a buyer when evaluating all Mercedes Benz fuel economy data. The SLK300’s fuel economy makes it a better choice against alternatives like a Porsche Boxster as it trades MPG for a sportier engine.

Tips to maximize efficiency

Use the “Comfort” mode for everyday driving. This setting adjusts the engine and transmission for fuel efficiency, making upshifts sooner and the throttle response smoother. Save the “Sport” mode for when you want to enjoy the car’s capabilities, as it will use more gas.

Watch traffic flow and avoid braking. Keeping a steady speed and avoiding sudden acceleration or slowing can improve fuel economy, especially in city driving. Look ahead and reduce your speed slowly.

Make sure your tires are inflated. Underinflated tires increase resistance, which makes the engine work harder and uses more fuel. Check your tire pressure and inflate them to the levels found on the driver’s side doorjamb.

Don’t idle. If you’re stopped for a minute, turn off the engine. The SLK300’s engine start/stop system does this automatically, but if the system is off or doesn’t activate, turning off the engine can save fuel.