What are 3-cylinder vehicles

Pros and cons: three-cylinder

Sebastian Renz likes the sound of the untamed

We finished the testing facility in Boxberg a little earlier than planned. The sun was shining. Too early to go home, too late to be seen at the company again. I decided to take the country lanes instead of the autobahn and started touring. It was a day to take down sports cars. Which, among other things, did not succeed in the first generation Citro├źn C1. But its one-liter three-cylinder engine snorted through the Hohenlohische, drummed its way enthusiastically up the speed limit, hissed, creaked, never gave up. I remember driving in sports cars that were less entertaining than this tour in the C1.

I know a lot of dull four-cylinder, could list five-, six- and eight-cylinder, of which I had expected more. But I've never driven a three-cylinder that disappointed me. Not even the weakest triple in the Smart. Because no other reciprocating engine revs up more enthusiastically in cars, speaks so greedily and sounds so motivated.

And they save the character of cars. With a four-cylinder, the old C1 would just be a cheap, windy, barren small car - and not a particularly good one on top of that. With its four-cylinder, the new Mini Cooper S is a full, overly motorized lifestyle bore. With the smaller, lighter, easy-revving 1.5-liter three-cylinder turbo, on the other hand, it whirls enthusiastically and feels as turned up as you would imagine from a Mini Cooper - especially when you consider how basically the old one 1.6-liter four-cylinder naturally aspirated engine failed to lively motorize the Cooper. Three-cylinders are also more compact, lighter and more economical - if someone still needs reasonable arguments for the more pleasurable engine.

In the three-cylinder test: Audi A1, against Mini One and Opel Adam

Heinrich Lingner is not a three-cylinder friend

Probably no one has said it aloud for a long time, but it remains true: three-cylinders are makeshifts. They are not built because they are particularly great, but because they are cheaper than four-cylinder engines with the same displacement. In addition, they have less internal friction, so theoretically consume a little less.

This is how they have come into vogue, making their way into the engine compartments, from small cars to plug-in sports cars. In order for these engines to run properly at all, they have to be sedated by a balancer shaft. Because a natural three-cylinder in a row rattles like a sack of nuts. If you don't believe that, I'll explain it briefly: Although a three-cylinder in-line engine has an even ignition angle, one of the three pops every 240 degrees of crankshaft rotation, but the ignition interval is large. In addition, at one end of the crankshaft a piston and connecting rod move downwards, while the third at the other end moves upwards at the same time. This leads to vibrations around the center of gravity in the middle of the crankshaft.

By the way, these are the reasons why straight six-cylinders run so smoothly: They are mirrored three-cylinders, the vibrations cancel each other out, and the ignition angle is only 120 degrees. V6 engines, on the other hand, are two three-cylinder engines with one crankshaft, which is why they require offset crankpins and balance shafts.

In case that is too academic for you: It was no coincidence that no four-stroke three-cylinder engines were installed in passenger cars until 1997: They ran too restlessly and the fuel consumption benefits were hardly measurable. The principle has not changed to this day, even if the tamed three-mans are barely noticeable of their fidgety nature.