[beepbeep]

Hello.

Turbo engines do have their drawbacks but in theory, they are more fuel efficient as turbochargers live off the entalpi of EGT before/efter the turbine.

There is a penalty of higher exhaust back-pressure and low C/R off boost but they are usually more efficient fuel-wise than N/A engines. Turbo-diesels certainly so.

Just check the history of reciproc airplane engines (before they got killed by jets).

First it was all pistons, then pistons + supercharger, then piston + turbocharger then piston + turbocharger + turbocompound.

So yes, they are more efficient if you make them so.

Unfortunately, not all manufacturers are able to make them more efficient.