What is the primary function of auxiliary braking systems such as the Engine Compression Brake (freno motor por descompresión / Jacobs) and the Hydraulic/Electromagnetic Retarder (retardador Telma)?

1. To bring the vehicle to an instant emergency standstill from 100 km/h
2. To provide continuous, non-friction deceleration during long descents, controlling speed without overheating and exhausting the mechanical service brakes
3. To replace the steering system during turns
4. To increase engine horsepower during uphill climbs