Hey everyone! A about a week ago I asked a question about turbos vs superchargers for reliability, and I think the general consensus between Chuck and Justin was that if the car was made with the supercharger it would be better for reliability. So, continuing that question why turbo chargers for fuel efficiency rather than superchargers, because they both ram more air into the engine just do it in different ways.
Obviously the turbocharger is operated by what would otherwise be wasted energy coming out of the exhaust, so it's almost like getting the mythical free lunch. The supercharger is engine-driven and robs some of the extra power that it creates.
Turbochargers take energy from the exhaust gas that would be wasted to the environment, and it spins a turbine on the intake side, pressurizing the intake gases. Run-of-the-mill turbochargers made by manufacturers aren't meant to be abused. Theoretically, they do get better gas mileage than the naturally aspirated engine equivalent in terms of displacement. Mind you, if you're also not hauling anything. Turbochargers that are constantly spooling up means the engine is running at high RPMs, which wears out the engine faster.
Superchargers don't require high engine speeds in order to start functioning, unlike the turbo, but you're always squeezing more air into the combustion chamber. More air requires more fuel, and you can't "turn off" a supercharger by going at lower RPMs; it's always running when the engine is running. That induces a loss in the engine.
operated by what would otherwise be wasted energy
Turbochargers take energy from the exhaust gas that would be wasted
I'm not sure it's 100% "waste energy". I think the engine still has to push against the turbo charger a bit.
Obviously, the gain is still net positive overall though.
