Reworked clutch behavior for better realism.
Changelog 6.2.0 Only 1.39.x

ENGINE compression factor:
- Increased Intensity of engine braking.

TRANSMISSION CHARACTERISTICS:
- Increased Retarder resistance factor.
- Decreased Flywheel resistance factor. (RPM loss)
- Adjusted when using clutch manual / automatic gearbox is taking off / changing gear.
- Increased torque converter-based transmissions.
- Increased relative magnitude of flywheel inertia
- Decreased transmissions inertia relative to the flywheel

- Added back support for modded trucks:

- BDF Tandem Truck Pack by Flemming
- DAF XF 105 by Vadik
- DAF XF 105 Rew by Schumi
- DAF XF Euro 6 Rew by Schumi
- Volvo FH 2009 by Schumi
- Scania New Generation By Eugene
- Volvo FH&FH16 2012 by Eugene

Changelog 6.1.3 (1.38.x; Older Versions)

ENGINE compression factor:
- Increased Intensity of engine braking.

TRANSMISSION CHARACTERISTICS:
- Increased Retarder resistance factor.
- Decreased Flywheel resistance factor. (RPM loss)
- Adjusted when using clutch manual / automatic gearbox is taking off / changing gear.
- Increased torque converter-based transmissions.
- Increased relative magnitude of flywheel inertia
- Decreased transmissions inertia relative to the flywheel