Documentation/Engine/Units/accessory transmission data

The accessory_transmission_data unit class is used to define the transmission characteristics for the player's vehicle, as well as the differential ratio. Units of this type are usually defined in /def/vehicle/truck/<brand.model>/transmission/*.sii and valid unit names end in .transmission.

Attributes

Many common attributes are inherited from accessory_data.

Name	Type	Default Value	Description
stall_torque_ratio	float	-1.0	Torque ratio multiplier if torque converter/multiplier is present. Any positive value is used as multiplier on lower RPM torque.
differential_ratio	float	1.0	This defines the differential/final drive ratio between the transmission output shaft and the wheels.
retarder	uint	0	The number of output levels for the retarder if applicable. If zero, retarder behavior is disabled for the transmission.
auxiliary_brakes	array<float3>		When set, this overrides the retarder control so that it controls both the retarder and engine brake. The components are (retarder strength, engine brake strength, downshift). The value of retarder must match the number of members in auxiliary_brakes. (Added in 1.28) For example: retarder: 5 auxiliary_brakes[]: (0.3, 0, 0) // 30% retarder only auxiliary_brakes[]: (0.6, 0, 0) // 60% retarder only auxiliary_brakes[]: (1.0, 0, 0) // 100% retarder only auxiliary_brakes[]: (1.0, 1, 0) // 100% retarder and 100% engine brake auxiliary_brakes[]: (1.0, 1, 1) // 100% retarder, 100% engine brake and downshift
ratios_reverse	array<float>		This defines the reverse gear ratios in order of decreasing gear reduction. The values should be negative. Example: ratios_reverse[0]: -11.002 ratios_reverse[1]: -8.875
ratios_forward	array<float>		This defines the forward gear ratios in order of decreasing gear reduction. The values should be positive. Example: ratios_forward[0]: 11.32 ratios_forward[1]: 9.132 ratios_forward[2]: 7.207 ...etc...
transmission_names	owner_ptr		Points to a unit of the type transmission_names, usually nameless and within the same unit definition file or included from a Serialized Unit Include (.sui) type file. This is used to assign custom names to each gear in automatic and sequential modes (these are overridden by h-shifter pattern definitions).
crawls	uint	0	The number of ratios_forward to handle as crawler gears for UI display. (Added in ETS2 1.27.2)