When it comes to six-cylinder engines, it's the inline-six that is the most common, followed by the V6. The flat-six is one of the least used six-cylinder engines across the board, although it does offer a great balance because of the three cylinders on each side of the central crankshaft.
A flat-six engine also has a low center of gravity and a shorter length and is often perfect for air-cooling as opposed to water cooling. One of the most common flat-six engines or perhaps the most well-known is the boxer-six engine made and used by Porsche for their sports cars, and it's also the reason behind the Boxster's name. Each pair of opposed cylinders in the boxer-six moves inwards and outwards at the same time.
It makes one wonder that if the flat-six engines are truly a marvel, why aren’t they more used in cars. The thing is, their large width makes them a tad bulky for front-engined cars and there are more parts required to get them air-cooled.
That said; there are still plenty of sports cars with flat-six engines, and here are ten of the best ones ever made.
10 Porsche 911 GT3: Perfect Track & Road Warrior
The Porsche 911 GT3 was introduced in 2013, bears a 493-horsepower 4.0-liter flat-six engine and is known to be one of the most track-focused and driver-friendly speedy cars out there. It has seen three generations and various revisions and remained a popular buy throughout.
That said, while the GT3 shines on the track, it's perfect for road use as well, and its cost is more than justified seeing the quality. Porsche 911s are the crème-de-la-crème of the lot, and the 911 GT3 simply becomes the cherry on the top.
9 Subaru XT6: The Legacy Of The Badge
Subaru has been a bit of an experimenter ever since it came into existence and you only have to look at the Brat and even the window-within-a-window concept of the SVX to know that. So when they debuted the XT6 in 1988, with a 2.7-liter flat-six engine that jetted 145 horses and 156 ft-lb torque, no one seemed surprised, despite that complicated steering system.
The XT6 may not have survived long, but this is the badging that remains on the Forester XT or even the Subaru XT to date.
8 Cayman GT4: A Future Classic
Long after the pandemic is a distant memory, the Porsche Cayman GT4 would probably be a hot classic. For now, with components sourced from the 911 GT3, which we already waxed eloquent about, the Cayman GT4 bears a 3.8-liter flat-six engine that makes 385 horses.
Built for just two model years, 2015 and 2016, this was one of the best mid-engine sports cars of the world, let alone from Porsche, although the engine came from the Carrera S. It may not be the fastest car around, but it definitely was one of the coolest.
7 Lykan HyperSport: Limited Edition Love
The Lykan Hypersport comes from W Motors, a Middle East-based automobile company, and only seven of these cars were ever made. One of them featured in the Fast & Furious franchise as well, though 10 of these were specially built for the movie with cheaper and easily destructible materials.
The engine in this comes from a German company, Ruf GmBH, a company that builds cars from unmarked Porsche chassis. The 3.7-liter twin-turbo flat-six engine is claimed to jet 740 horses and 960 ft-lb of torque in a car so edgy, it could cut.
6 Porsche Cayman GTS (981): The Latest Flagship
The 3.4-liter flat-six engine in the Cayman GTS jets 340 horses, letting this cool car run at top speeds of 177 mph. The GTS is a step above the Cayman S and comes with the Porsche Active Suspension Management system for the smoothest, sportiest ride in town.
The insides are a pleasant blend of leather and Alcantara and this car is perfect for those who lust after the GT4 but cannot quite get it. This is the perfect car to do your daily driving in and still get plenty of kicks on the highway as well.
5 911 Sport Classic (997): The 2010 Limited Edition
Only 250 units of the Porsche 911 Sport Classic were made, running on a 3.8-liter flat-six engine that jetted 408 horses since it came fitted with the engine Powerkit. The 310 ft-lb torque was respectable as well, and enough to take this car to 60 mph in 4.6 seconds, with top speeds of 187 mph.
To some, it looked like just a 911 Carrera S with a ducktail, but the double-bubble roof, as well as the modifications under the hood, made it way more stylish than the Carrera S. Plus it drove a lot sportier too.
4 Fenyr SuperSport: The Lykan Successor
Once all seven of the Lykan Hypersport were made and sold, W Motors moved on to the Fenyr SuperSport, this time powered by a 3.8-liter twin-turbo flat-six that jetted 789 horses and 723 ft-lb torque.
The Fenyr, much like the Lykan, comes named after werewolves and can hit 52 mph in 2.8 seconds, with top speeds of 248 mph. Looks-wise, it comes simpler than the Lykan, although it costs a cool $1.5 million as well, and is as exclusive as they come, with only 100 models planned.
3 Porsche Targa GTS (991.2): Looks Good, Runs Better
The Targa GTS debuted in 2017 and can go top speeds of 188 mph, with a 3.0-liter flat-six that jets 450 horses and 408 ft-lb torque. Obviously, it’s a Porsche, and Porsches are super cool cars. And the Targa models look a class apart, with the wrapped rear glass and the soft top with the off-color pillar.
The GTS feels faster than the other Targa models as well, and yet, even with the roof down, the wind in your hair does not feel like a storm. Hitting 62 mph is a cool 4.1 seconds.
2 Porsche 911 Carrera S (991.2): Better Power & Cool Factor
Seems like a lot of Porsche on this list, but then again, the flat-six has a steady home with this brand in its various models. The 911 Carrera S debuted in 2016 with a 3.0-liter flat-six jetting 416 horses, some 50 horses more than the regular Carrera.
The Carrera S has more power and gear over the stock Carrera, and while the engine does not sound like a naturally-aspirated one, because it isn’t, it's still a gorgeous car with a supercool mill.
1 Porsche Boxster Spyder (987): The Niftiest Of Them All
Debuting in 2011, the Porsche Boxster Spyder came rigged with the 3.4-liter flat-six engine that boasted direct-injection, taken from the Cayman of the same year. What most people loved about the car was that it was a sporty build of a Boxster, and took an everyday car to sporty indulgence.
The steering is cool and the deck lid, spoiler, and windshield rake are pretty awesome as well, plus the car is not just fun to drive but supremely efficient as well. Much like most of the Porsches!
Sources: Hooniverse, Autoweek