The 3 cylinder cars of the 1980s, such as the Geo Metro, Subaru Justy and Daihatsu Charade were quite thrifty but rather unrefined.  The engines in those cars weren't balanced terribly well because of basic physics of three pistons moving around. Because two of the pistons move up and down in the cylinders at the same time, a three-cylinder engine is naturally unbalanced. Plus, these three bangers delivered really low performance.  Here's an example: the 1.0-liter engine in the Charade, sold here in the states from 1988 to 1992, generated just 53 hp and needed a full 15 seconds to reach 60 mph. Perhaps it's only strong suit: a respectable 38 mpg highway fuel economy rating.

Today the second coming of the 3 cylinder engine has occurred. The new Ford Fiesta SFE is a three banger, 1.0-liter engine that is rated at 123 hp, over twice that of the old Daihatsu Charade.  It carries an EPA rating of 45 mpg on the highway and can move the Fiesta -- which weighs 800 pounds more than the Charade -- to 60 mph in less than 8 seconds.

Automakers are turning to threes for a number of reasons: Smaller engines reduce vehicle weight, which improves handling and braking. Also, three-cylinder engines use roughly 20 fewer parts than four-cylinders and are thus cheaper to build. And, because the engines are so compact, they can help improve safety in front-end crashes. This is because with more space around the smaller engine, the chances of it penetrating the interior in a severe high-speed crash are reduced. 

What is not yet known is how consumers will accept the modern three-cylinder. Ford, BMW and other automakers are not drawing attention to the number of cylinders in their three cylinder cars. That's due in part to the reputation of older three-cylinder engines. Instead, their message focuses on performance and fuel economy.