It turns out there is a replacement for displacement.
Though the era of downsizing isn't all it's cracked up to be in the economy stakes, the era of the turbocharger sure has its benefits. Most crucially, the addition of turbos has huge benefits for the torque output of an engine, with power taking a bump beyond its regular potential too. Keith Duckworth – engineer for Cosworth – once said that "turbochargers are for people who can't build engines." Nowadays turbochargers are magical ways of enhancing a great engine and making it better, turning 4-cylinder motors into V8-killers. That's big talk, and the traditionalists are picking up their torches and pitchforks as I write this, but these 4 cylinder engines prove that statement to be true.
All three of these Volkswagen-family products make use of the same EA888 high-performance 2-liter engine that's been doing duty since the Mk V Golf GTI. It's been a tuner's delight since the early days, and with time, engineering has only made it better. In its current incarnation the turbocharged inline-4 boots out 292 horsepower and 280 lb-ft of torque. A 2001 Mustang Bullitt only had outputs of 265hp from its 4.6-liter V8, and the turbo-4 means torque is available freely through the rev-range for improved acceleration. The engine has been proven to exceed 400hp too, in VW's Golf R400 concept.
Though the Alfa Romeo Giulia is often defined by its 50:50 weight balance, carbon fiber driveshaft, and the M3-baiting Quadrifoglio's Ferrari-derived 503hp V6 engine, the base models offer some impressive clout too. Powered by a new all-aluminum turbocharged 4-cylinder displacing 2.0-liters, in its highest state of tune the motor sends 280 hp and 306 lb-ft of torque to the rear wheels through an 8-speed automatic gearbox. There's an optional all-wheel-drive system too, which enables a 0-60 mph sprint of quicker than 5 seconds. Chevrolet's V8-powered Camaro of 1996 had a comparable 285 hp – proving how in just 20 short years the humble 4-cylinder has improved.
The Mercedes-AMG CLA 45 and GLA 45 have become modern-day halo cars for the diminutive 4-cylinder. Rivaling BMW's 3.0-liter turbo-6 and Audi's turbo 5-pot, the AMG 45 range punches way above its weight. With the new ones expected to eclipse 400 hp. Currently, the 2.0-liter unit generates 376 hp and 350 lb-ft of torque, nearly matching the outputs of a 2011 Mercedes-Benz E500, despite the latter boasting a 5.5-liter naturally aspirated V8 worth 383 hp. The CLA 45 though is vastly quicker, eclipsing the E500's 0-60 mph time by more than a full second.
It's not just modern turbo-4s that provide immense power for their outputs. As far back as the early 2000s the Subaru Impreza WRX STi and Mitsubishi Evo were thumping giant-killers. The biggest giant-killer of them all was the Mitsubishi Lancer Evo X FQ400 of 2010, which produced 403 hp and 387 lb-ft, and claimed the 0-60 mph sprint in a supercar-bating 3.8 seconds. A 2010 Mustang GT only had 315 hp and 325lb-ft from its 4.6-liter V8, proving there is a replacement for displacement.
For decades, Volvo was seen as the brand that epitomized safety, and performance was the last thought in their engineers' minds. But with Polestar now pursuing electrified performance, it's a new era for the brand. The Volvo S60 and V60 Polestar models gave us a preview of just what the performance arm could do, taking a 2.0-liter Drive-E four-cylinder engine, equipping it with both a turbocharger and a supercharger, thus giving it 36 2hp and 350 lb-ft – making it more powerful than the original AMG CLA 45, and more powerful than a C5 Corvette.
What does it take to make a front-wheel-drive hatchback conquer the Nurburgring quicker than a 2004 Ford GT? Well, all it takes is a little boost, and when the Japanese brand finally succumbed to the notion of forced induction it paid dividends. The current FK8 Type R uses a 2.0-liter turbo-4 that generates up to 316 hp in Japan, though US versions only output 306 horses, which is still more than a C4 Corvette, and vastly quicker on the street and around a racetrack.
Though the Ford Mustang EcoBoost might seem the obvious addition to this list, with a turbocharged 2.3-liter 4-cylinder rivalling V8's of old, that engine was developed further for inclusion in the Ford Focus RS – Ford's mighty all-wheel drive drift-mode enabled super-hatch. Well in the Focus RS, that 2.3-liter generates a mighty 350 hp and equal amounts of torque, 35 hp more than a 2010 Mustang GT and with 25 lb-ft more twist. But the Focus RS also does 0-62 mph in 4.7 seconds, quicker than a 2014 Dodge Charger SRT8.
The world has rued Porsche's decision to downsize the Cayman and Boxster to 4-cylinder turbocharged engines – after all, they do sound like hyped up Hoovers more than top-class sports cars. But, the 4-cylinder's efficacy can't be denied, and in no place is this on display more than in the 718 Cayman and Boxster GTS models.
The 2.5-liter turbocharged flat-4 generates 365 hp and 309 lb-ft. Impressive figures, stronger than many a classic V8, but it's the performance those figures give that's most impressive, resulting in a 0-60 mph time of 3.9 seconds – as quick to the mark as a C6 Corvette.
BMW is on the verge of going front-wheel-drive with a range of its smaller vehicles, as we've already seen on the X1 and X2 models. With the change in drivetrain they've also given us new engines for the application, including the M35i denomination models with a 2.0-liter turbo-4 worth 302 horsepower and 332 lb-ft – more power than a 2003 BMW 540i which was equipped with a 4.4-liter V8. Less than half the displacement, with more power, a better torque curve, and greater efficiency – welcome to the age of the turbo!
In 2018, the Subaru WRX STI's 310 hp is well within the competitive ranks of its class, more than the Golf R and the Civic Type R. But the EJ257 motor at its heart, a 2.5-liter turbocharged flat-4, has been in the US since 2004 outputting 300 hp – the same as the Ford Mustang of the same year. Paired with all-wheel drive, the WRX STI has consistently punched above its weight, both in a straight line and around the racetrack, proving a 4-pot is more than capable of holding its own against a V8.
Though most pine over the Jaguar F-Type's supercharged 5.0-liter V8, the entry-level 2.0-liter turbo-4 represents the huge potential of the humble 4-cylinder. Part of the brand's new Ingenium line-up of engines, the modular 4-cylinder is turbocharged to produce 296 hp and 295 lb-ft. 0-60 mph takes 5.4 seconds, only slowed by the F-Type's relatively heavy weight figure. In Sport mode, the sound system may pipe in false V6 noises, but the performance on offer is all 4-cylinder.