The G60. It's one of the more legendary labels in Volkswagen's past. If you're familiar with the Corrado, you probably already know that the G means supercharger but knowing why it got that label is a bit more mysterious. Not why it got the supercharger, that's pretty obvious, but instead where the G came from. And the 60, for that matter.

It turns out it's short for G-Lader. Lader is the German word for supercharger, and the G refers to the shape of the unit. That's because this isn't your conventional supercharger, like the ones found on dozens of different models over the years. No, instead this one is uniquely VW.

The common types of supercharger that you likely already know are Roots and centrifugal. The Roots blower has been used for decades on everything ranging from the Corvette to, well, actual corvettes. Like, big diesel ships.

They use two long lobes that interlock, with a large gap at the intake end and a smaller gap at the end that leads to the engine. As the air is pushed down the lobes, it gets compressed. Simple and effective.

The other type is the centrifugal supercharger. That's a popular aftermarket solution that is basically the business end of a turbocharger, but instead of an impeller turbine spun by the exhaust flow, the drive comes usually from a belt or shaft driven by the engine. That lets the aftermarket installers put it wherever they need to, which is why it's popular for that type of install.

Volkswagen's G-Lader is a scroll-type supercharger, which gets talked about a whole lot less even though it's actually one of the oldest designs. Patented way back in 1905, manufacturing at the time wasn't capable of actually building one that worked properly.

It's a strange design, and if it looks and sounds more complicated than the other types of supercharger, that's because it is.

The moving part of the G-Lader is a plate, called a displacer, that has two spirals sticking out of each side. Those spirals are the scrolls. They fit inside fixed scrolls on each side of the body of the supercharger.

When driven by the crankshaft, the displacer plate moves in a circle. That moves its spirals inside the fixed spirals of the outer housing. When it moves in one direction, the gap between the two gets bigger, pulling air in. As it continues in the circle, they move closer together and the air is compressed. When it's compressed, it's forced into the engine, and that's how it makes boost.

The Spirals Look Like This, Just with Fewer Coils (via Wikipedia)​

Volkswagen said it didn't' need maintenance, which is the easiest way to make sure that a part needs maintenance. The G-Lader was no exception, so they often needed repair. Which is why they didn't take all that many years to disappear from the market. But many of the internal parts are available, even today, so you can maintain and rebuild the units as needed.

Why did VW pick this option? Well, they were quiet, and they were more efficient than other types of forced induction. Plus they didn't have the lag of a turbocharger, which was a much larger concern in the 1980s than it is today.

There were two versions of the G engine. One called the G40 that was a 1.3L four found in the MK2 Polo. then there was the G60, a 1.8L engine that made up to 207 hp and was put in the MK2 Golf, B3 Passat, and the Corrado. The number refers to the depth of the scrolls, in mm.

It was a promising bit of tech that ultimately didn't quite work in the field. But at least the next time you see a G60 badge in the grille, you'll know what it's all about.