The days of the internal combustion engine may be numbered with the rise of electric vehicles, but right now they’ve never been more powerful, varied or sophisticated.
At the extreme end of the engineering spectrum is the massively “over the top” complexity of the Volkswagen group’s W16 engine, which has found its way into the Bugatti Veyron, Bugatti Chiron and others. You can think of it as two narrow V8 engines side by side with a common crankshaft and no less than four turbochargers. In the impressively named Bugatti Chiron Super Sport 300+ it generates an astonishing 1177kw, which I guess is pretty handy if you need to pop down to the shops in it for a litre of milk.
Sitting at the polar opposite of this piston extravaganza is the increasing popularity of three-cylinder engines. Three-cylinder motors have been around for a while, with Daihatsu, a subsidiary of Toyota, putting them into its Charade and other vehicles from the late 1980s.
Today they’re having their day in the sun with the Ford Fiesta ST, the Toyota GR Yaris and the Mini Cooper just a few examples.
Now if you’re thinking that if it has three cylinders it must be some cut-price, gutless, rough-running buzz box compared to a “proper” four-cylinder vehicle, well you can think again. Because modern three-cylinder motors are very powerful yet remarkably fuel efficient.
One of the finest examples is the Toyota GR Yaris. The turbocharged 1.6 litre three cylinder under the bonnet has transformed a competent little shopping trolley into a rip snorting, hairy-chested, giant-killing beast of a thing.
That 1.6 litre engine puts out 200kw at 6500rpm and 370Nm from 3000-4600rpm. Toyota believes its rally car for the road has the most powerful mass produced three-cylinder engine in production.
So what is it about three-cylinder engines that’s suddenly making them the little darling of the motoring world?
Well you can thank turbocharging for a lot of it. When you pump more air into an engine through a turbocharger you get a lot more power out of it, and turbochargers have really come of age lately.
Light and powerful
With fewer cylinders comes less size and weight. A smaller engine takes up less space in a car, so there’s more room for more important things, like passengers and luggage. Less weight is also good because the engine is using less power simply lugging its own weight about.
Three-cylinder engines are also inherently more efficient because there’s fewer moving parts inside that engine producing less friction for the same amount of power.
And there’s one more reason why carmakers like that compact size: safety. Engineers need to design a crumple zone in front of an engine to absorb the impact of a crash. A smaller engine makes that a lot easier.
The advantages for carmakers don’t end there, because three-cylinder engines are cheaper to make. Fewer cylinders mean fewer components. That makes for a cheaper engine that’s quicker to assemble as well, saving valuable time on the production line. As Benjamin Franklin famously observed back in 1748, “time is money”.
For all these reasons, when it comes to really efficient internal combustion engines you can forget about uber expensive exotica like the Volkswagen group’s W16 and look instead at modern turbocharged three cylinders. Because when it comes to engines, less really is more.