For years, the world’s most aerodynamic cars have been sleek, streamlined racers that used advanced engineering to cheat wind resistance and gain precious speed. These cars spent countless hours in wind tunnels, with engineers reviewing every detail of a car to make it as slippery as possible. Wind resistance not only reduces speed, it’s terrible for fuel economy. With the U.S. government’s Corporate Average Fuel Economy laws mandating that carmakers have a fleet average of 34.1 miles per gallon for the 2016 model year, carmakers are now lavishing the same attention to aerodynamic detail on subcompacts as they are on sports cars – with astonishing results.
The most common way to measure a car’s aerodynamics is to calculate the drag coefficient, or Cd. Tested in a wind tunnel, the drag coefficient is a measure of how air passes over the front of a car; the lower the drag, the more aerodynamic the car is. The average drag coefficient for a production car is between 0.30 and 0.35, but surprisingly, many of the world’s fastest cars create much more drag. They use spoilers and vents to create downforce, keeping them planted firmly on the ground at speed. Because of this, most of the world’s most aerodynamic cars aren’t speed machines, they’re fuel-sipping sedans.
Recent innovations like underside cladding, smaller grille openings, and wind flaps that close at speed are details that have turned economy-minded daily drivers into technological marvels. Along with with smaller engines and higher-geared transmissions, average fuel economy is growing in leaps and bounds. From 200-mile-per-hour sports cars to sensible five-door hybrids, here are 10 of the most aerodynamic cars in the world.
10. BMW i8
The i8 is nothing short of a technological triumph. With complex carbon-fiber construction, the avant-garde i8 sports a twin-turbo 1.5 liter three cylinder gasoline engine paired with an electric motor good for a total 357 horsepower. The lightweight supercar can go zero to 60 in 3.8 seconds. More importantly, the hybrid drivetrain and 0.26 drag coefficient ensure the car gets 28 miles per gallon – an astonishing feat for a such a high-performance car.
9. Jaguar XE
Touted as “the most efficient, advanced, and refined sports saloon car that Jaguar has ever produced,” the XE is an aluminum-bodied contender designed to take on the likes of the BMW 3-Series and Mercedes-Benz C-Class. Jaguar’s attention to aerodynamics make the XF one of the slipperiest cars on the road today, with a drag coefficient of 0.26.
The Mazda3 has long been one of the best small sedans in the world. Fantastic handling, beautiful styling, and better aerodynamics than a Ferrari. The slippery design gives the car a drag coefficient of 0.26, making the Mazda the most aerodynamic car in its class – and one of the most efficient, with a combined fuel economy rating of 33 miles per gallon.
7. Mercedes-Benz B-Class
Mercedes-Benz is famous for their wind tunnel testing, and they’ve made no exception for their subcompact B-Class. The all-electric version of the car hit U.S. showrooms last summer, and the small Benz is a solid competitor against the Nissan Leaf and BMW i3. The car has a drag coefficient of 0.26, making it far more slippery than the 0.29 Cd BMW i3 and 0.28 Cd Leaf. Mercedes’ attention to aerodynamics helps the B-Class go 87 miles on a single charge.
6. Nissan GT-R
The Nissan GT-R is a true overachiever. With a 545 horsepower twin-turbo V6 and a top speed of 196 miles per hour, the GT-R is one of the most formidable sports cars in the world. Its impressive 0.26 drag coefficient helps take the car from zero to 60 in under three seconds, making it one of the fastest accelerating cars in the world. Performance-wise, there really isn’t much the GT-R can’t do.
5. Toyota Prius
No other car represents a commitment to fuel economy quite like the Toyota Prius. With the car’s proven hybrid drivetrain and a real-time miles per gallon readout, the Prius is more responsible for hypermiling than any other car. Toyota’s instantly recognizable wedge-shape gives the car an ultra-low drag coefficient of 0.25, which helps the car get around 50 miles per gallon.
4. Mercedes-Benz S-Class
Mercedes’ commitment to aerodynamics is a hallmark of its flagship S-Class. While improved fuel economy is an important detail (the car gets a combined 20 miles per gallon, up from the last model’s 19), the S-Class spent most of its time in the wind tunnel testing for one reason: silence. With a drag coefficient of 0.24, the Mercedes engineers’ work paid off handsomely – the S-Class-based Maybach S600 is the quietest production car in the world.
3. Mercedes-Benz C-Class
Unlike the flagship S-Class, Mercedes has used the wind tunnel to turn their new C-Class into a formidable sport sedan. While the BMW 3-Series has long held a sportier reputation than the Mercedes, the new C-Class sports nearly identical performance numbers to the BMW, thanks in part to class-leading aerodynamics and a drag coefficient of 0.24.
2. Tesla Model S
No car has done more to transform public perception of electric cars like the Tesla Model S. Beautifully designed, impressively safe, and incredibly fast, the Model S also took top honors in Car and Driver’s wind tunnel test for the most aerodynamic car of 2014. While the Tesla’s drag coefficient of 0.24 is impressive, it doesn’t come anywhere near the slipperiest car in production…
1. Volkswagen XL1
If speed wasn’t a factor in what makes a supercar, then the XL1 would rank as one of the best ever. With an incredible drag coefficient of 0.189, the XL1 is the most aerodynamic car ever to go into production. Everything about the 313 mile per gallon XL1 was designed for fuel economy. A front grille and side view mirrors were sacrificed in the name of aerodynamics, and the rear wheels were covered up to lower wind resistance. Advanced carbon fiber construction, and a two-cylinder hybrid engine keeps the car’s weight well under one ton. Volkswagen built 25o XL1’s, but unfortunately the $167,736 cars are only available in Europe.
The XL1 may look extreme, but it offers a unique glimpse into the future of production cars. With U.S. fuel economy standards rising to a targeted 54.5 miles per gallon by 2025, aerodynamics will only become more important in future car designs. Today, these 10 cars rank among the most aerodynamic in the world, and they make the benefits of advanced aerodynamics abundantly clear. For performance and fuel economy, aerodynamics are the way of the future for mass-market production cars.