Methods and systems are described for enhanced engine friction generation. The enhanced engine friction generation improves the effectiveness of vehicle braking in deceleration fuel cut-off driving conditions by using engine vacuum and backpressure to temporarily increase engine pumping losses, thereby increasing powertrain drag and increasing deceleration torque to the wheels. The engine vacuum and backpressure may be created by changing the duration of the intake and/or exhaust valves. The system includes a processor and a non-transitory computer-readable storage medium storing instructions that, when executed by the processor, cause the processor to perform operations comprising adjusting an intake valve time duration or an exhaust valve time duration to increase engine friction to enhance mechanical friction on a drivetrain of a vehicle.