diff --git a/DynObj.cpp b/DynObj.cpp
index 7fef6ed5..9cbd8950 100644
--- a/DynObj.cpp
+++ b/DynObj.cpp
@@ -7569,13 +7569,13 @@ TDynamicObject::powertrain_sounds::render( TMoverParameters const &Vehicle, doub
     }
 
 	if (Vehicle.hydro_R) {
-		float speed = std::abs(Vehicle.hydro_R_Fill * Vehicle.hydro_R_n);
+		float speed = std::abs(Vehicle.hydro_R_n);
 
 		retarder
 			.pitch(retarder.m_frequencyoffset + speed * retarder.m_frequencyfactor)
 			.gain(retarder.m_amplitudeoffset + Vehicle.hydro_R_Fill * retarder.m_amplitudefactor);
 	
-		if (retarder.gain() > 0.01) {
+		if ((retarder.gain() > 0.01)&&(speed > 1)&&(Vehicle.hydro_R_ClutchActive)) {
 			retarder.play(sound_flags::exclusive | sound_flags::looping);
 		}
 		else {
diff --git a/McZapkie/MOVER.h b/McZapkie/MOVER.h
index 82f67da5..2e70d0ae 100644
--- a/McZapkie/MOVER.h
+++ b/McZapkie/MOVER.h
@@ -1277,6 +1277,9 @@ public:
 	double hydro_R_FillRateDec = 1.0; /*szybkosc oprozniania sprzegla*/
 	double hydro_R_MinVel = 1.0; /*minimalna predkosc, przy ktorej retarder dziala*/
 	double hydro_R_EngageVel = 1.0; /*minimalna predkosc hamowania, przy ktorej sprzeglo jest wciaz wlaczone*/
+	bool hydro_R_Clutch = false; /*czy retarder ma rozłączalne sprzęgło*/
+	double hydro_R_ClutchSpeed = 10.0; /*szybkość narastania obrotów po włączeniu sprzęgła retardera*/
+	bool hydro_R_WithIndividual = false; /*czy dla autobusów jest to łączone*/
     /*- dla lokomotyw spalinowo-elektrycznych -*/
 	double AnPos = 0.0; // pozycja sterowania dokladnego (analogowego)
 	bool AnalogCtrl = false; //
@@ -1576,6 +1579,7 @@ public:
 	double hydro_R_Torque = 0.0; /*moment*/
 	double hydro_R_Request = 0.0; /*zadanie sily hamowania*/
 	double hydro_R_n = 0.0; /*predkosc obrotowa retardera*/
+	bool hydro_R_ClutchActive = false; /*czy retarder jest napędzany*/
 
     /*- zmienne dla lokomotyw z silnikami indukcyjnymi -*/
 	double eimic = 0; /*aktualna pozycja zintegrowanego sterowania jazda i hamowaniem*/
diff --git a/McZapkie/Mover.cpp b/McZapkie/Mover.cpp
index 8fae3534..889e210f 100644
--- a/McZapkie/Mover.cpp
+++ b/McZapkie/Mover.cpp
@@ -7822,6 +7822,7 @@ double TMoverParameters::dizel_Momentum(double dizel_fill, double n, double dt)
 double TMoverParameters::dizel_MomentumRetarder(double n, double dt)
 {
 	double RetarderRequest = (Mains ? std::max(0.0, -eimic_real) : 0);
+	if (hydro_R_WithIndividual) RetarderRequest = LocalBrakeRatio();
 	if (Vel < hydro_R_MinVel)
 		RetarderRequest = 0;
 	if ((hydro_R_Placement == 2) && (enrot < dizel_nmin))
@@ -7829,7 +7830,21 @@ double TMoverParameters::dizel_MomentumRetarder(double n, double dt)
 		RetarderRequest = 0;
 	}
 
-	hydro_R_n = n * 60;
+	hydro_R_ClutchActive = (!hydro_R_Clutch) || (RetarderRequest > 0);
+	if ((!hydro_R_Clutch)
+		|| ((hydro_R_ClutchActive) && (hydro_R_ClutchSpeed == 0)))
+	{
+		hydro_R_n = n * 60;
+	}
+	else if (hydro_R_ClutchActive)
+	{
+		hydro_R_n = sign(n)*std::min(std::abs(hydro_R_n + hydro_R_ClutchSpeed * dt), std::abs(n * 60));
+	}
+	else
+	{
+		hydro_R_n = 0;
+	}
+	n = hydro_R_n / 60.f;
 
 	if (hydro_R_Fill < RetarderRequest) //gdy zadane hamowanie
 	{
@@ -7841,7 +7856,7 @@ double TMoverParameters::dizel_MomentumRetarder(double n, double dt)
 	}
 	
 	double Moment = hydro_R_MaxTorque;
-	double pwr = Moment * n * M_PI * 2 * 0.001;
+	double pwr = Moment * std::abs(n) * M_PI * 2 * 0.001;
 	if (pwr > hydro_R_MaxPower)
 		Moment = Moment * hydro_R_MaxPower / pwr;
 	double moment_in = n*n*hydro_R_TorqueInIn;
@@ -10630,6 +10645,9 @@ void TMoverParameters::LoadFIZ_Engine( std::string const &Input ) {
 					extract_value(hydro_R_FillRateDec, "R_FRD", Input, "");
 					extract_value(hydro_R_MinVel, "R_MinVel", Input, "");
 					extract_value(hydro_R_EngageVel, "R_EngageVel", Input, "");
+					extract_value(hydro_R_Clutch, "R_IsClutch", Input, "");
+					extract_value(hydro_R_ClutchSpeed, "R_ClutchSpeed", Input, "");
+					extract_value(hydro_R_WithIndividual, "R_WithIndividual", Input, "");
 				}
 			}
             break;