Want a car that uses less fuel? How about cutting down on the number of cylinders in the engine? Better yet, why not start with four cylinders and take away one?
In theory, three-cylinder engines should have been a great solution to achieving high MPG decades ago but didn’t quite pan out so well in practice. It wasn’t because the technology was bad; rather, the problem was execution.
Three-cylinder cars of the 1980s, such as the Daihatsu Charade and the Geo Metro, were quite thrifty but unrefined, mainly because their engines weren’t balanced well in accordance to basic physics. That is, because two of the pistons move up and down in the cylinders simultaneously, a third-cylinder naturally makes things unbalanced.
A result of this poor balance is relatively low performance. Case in point, the 1.0-liter engine found in the Charade — a 2,000-pound compact hatchback that was sold in the United States from 1988 to 1992 — produced a mere 53 hp and required a full 15 seconds to accelerate the tiny car from 0 to 60 miles per hour. Perhaps its only redeeming feature? A respectable, EPA-estimated 38 MPG fuel economy rating in highway driving.
The Ford Fiesta SFE of today, by comparison, showcases how today’s technology has transformed the 3-cylinder engine into something to be respected. The laws of physics still cause a balance issue but engineers have created workarounds.
The Fiesta SFE’s engine is the same size as the old Charade’s 1.0-liter but it is rated at a notably more impressive 123 hp, over twice that of the Charade. Its EPA rating is also approximately 3 mph higher at 41 mpg in highway driving.
Wade Jackson, the Fiesta’s brand manager, says no promotions are currently planned to point out that the Fiesta has a three-cylinder engine. Instead, the focus is on gas mileage. With the Mitsubishi Mirage, another small hatchback with a frugal 3-cylinder engine, Mitsubishi’s focus was quite economic: providing an affordable entry-level car that offers the fuel economy of a hybrid or diesel, but at a lower price.
The engineering goal of both the Fiesta and Mirage was to cut down the vehicle’s overall curb weight to enable the engine to deliver good performance. The Mirage, in particular, weighs just 1,863 pounds and can reach 60 mph from a standstill in about 11 seconds.
Auto manufacturers are increasingly turning to threes for several of reasons:
Smaller engines reduce a car’s overall weight, improving handling and braking.
- Three-cylinder engines use about 20 fewer parts than four-cylinders and are, thus, less expensive to build.
- The engines are very compact, helping improve safety in front-end crashes (the chances of it crashing into the interior in a severe high-speed accident are reduced).
- They deliver diesel-like levels of fuel economy for a much lower cost.
Did you know that the sexy, highly-capable BMW i8 hybrid sports car is partly powered by a three-cylinder engine?
What’s not yet known is how drivers will accept the modern three-cylinder. Ford, BMW and other auto manufacturers are not drawing attention to the number of cylinders due in part to the gutless reputation of older 3-cylinder engines. Instead, the Sales Manager at Patrick BMW, a full-service car dealer in Schaumburg, IL. tell us that the message of automakers focuses on performance and fuel economy.