To get parameters used in reports, use the command unit/get_report_settings:

svc=unit/get_report_settings&params={"itemId":<long>}

{
	"speedLimit":<uint>,		/* speed limit, km/h */
	"maxMessagesInterval":<uint>,	/* maximum interval between messages, seconds */
	"dailyEngineHoursRate":<uint>,	/* daily engine hours rate, hours */
	"urbanMaxSpeed":<uint>,		/* urban speed limit, km/h */
	"mileageCoefficient":<uint>	/* mileage coefficient */
}