Forced induction has become the default way to add power without sacrificing efficiency, and the turbocharger is the most common example.
It uses exhaust gases to spin a turbine and an impeller that pushes more air into the engine, creating boost.
Turbochargers now appear in everything from small three-cylinder hatchbacks to million-dollar exotics.
Historically, their main drawback has been turbo lag, because the engine needs to rev past a certain point before the turbo starts working.
How Twincharging Solves Turbo Lag
Electric turbochargers, such as those used in the new Porsche 911 Turbo S, have largely addressed lag in recent years.
A small electric motor on each turbo brings it up to speed instantly, eliminating the delay.
Before e-turbos arrived, some manufacturers turned to twin-charger systems, combining a supercharger with a turbocharger.
The idea is straightforward: a supercharger is typically driven by the crankshaft, so it pumps more air without a boost threshold.
That lets it deliver low-rpm power while the turbo takes over once exhaust gases spin it into life.
Why So Few Cars Use Both
Only a small handful of production cars have ever been sold with twin-chargers.
They include the Mercedes-AMG E 53, Lancia Delta S4, Skoda Fabia RS, Audi SQ7, Zenvo ST1, and the more recent Kimera EVO37 restomod.
Combining a turbocharger and a supercharger may sound like the best of both worlds, but the drawbacks are obvious.
Most notably, installing both adds weight, complexity, and cost.
A turbo alone already requires several extra parts in the engine bay, including an intercooler, boost pipes, a unique intake manifold, and the turbo itself.
A supercharger needs an additional pulley off the crankshaft and the supercharger unit, usually positioned on top of the engine.
All of this adds cost, and the extra complexity means more failure points and repairs that can be a headache.
That helps explain why few brands have committed to developing and building twin-charged cars.
For anyone considering forced induction, the practical choice is usually between a turbo or a supercharger, not both.
