V12 engine
Each cylinder bank is basically a straight-6. This set-up has perfect balance no matter which V angle is used. A V12 engine does not need balance shafts. A V12 angled at 45°, 60°, 120°, or 180° from each other has even firing and is smoother than a straight-6. This provides a smooth running engine for a luxury car. In a racing car, the engine can be made much lighter. This makes the engine more responsive and smoother. In a large heavy-duty engine, a V12 can run slower, and  prolonging engine life.