Create folders in your user folder so it looks like this C:\Users\yourusername\Documents\BeamNG.drive\lua\vehicle\powertrain\ and move the \Steam\steamapps\common\BeamNG.drive\lua\vehicle\powertrain\combustionEngineThermals.lua to the above folder to avoid overwrite official content Open the lua file via notepad (notepad++ is recommended) and scroll to line 517 Code: local radiatorActive = min((hasCoolantRadiator and M.coolantTemperature > thermostatTemperature and not parentEngine.isDisabled) and M.coolantTemperature - thermostatTemperature or 0, 1) change it to Code: local radiatorActive = min((hasCoolantRadiator and M.coolantTemperature > thermostatTemperature and not parentEngine.isDisabled) and (M.coolantTemperature - thermostatTemperature)/thermostatRange or 0, 1) Scroll to line 1167 and add the following text between line 1167 and line 1168 Code: thermostatRange = jbeamData.thermostatRange or 1 Save it. Then mod your vehicle, in this example the ETKI. Create the vehicle folder in your user folder C:\Users\yourusername\Documents\BeamNG.drive\vehicles\etki\ Copy the radiator jbeam flie, in this example, the \Steam\steamapps\common\BeamNG.drive\content\vehicles\etki.zip\vehicles\etki\etki_radiator.jbeam into the C:\Users\yourusername\Documents\BeamNG.drive\vehicles\etki\ AND RENAME IT open the jbeam file and rename the "etki_radiator" and "name":"Radiator", Add the "thermostatRange" below the "thermostatTemperature" Spoiler: Example Code: { "etki_radiator_thermod": { "information":{ "authors":"BeamNG", "name":"Radiator(thermostat mod)", "value":130, } "slotType" : "etki_radiator", "flexbodies": [ ["mesh", "[group]:", "nonFlexMaterials"], ["etki_radtube", ["etki_engine","etki_radiator"]], ["etki_radiator", ["etki_radiator"]], ], "mainEngine":{ "radiatorArea":0.34, "radiatorEffectiveness":7500, "coolantVolume":8, "radiatorFanType":"electric", "radiatorFanTemperature":100, "radiatorFanMaxAirSpeed":2, "thermostatTemperature":80, "thermostatRange":20, }, "nodes": [ ["id", "posX", "posY", "posZ"], //radiator {"frictionCoef":0.5}, {"nodeMaterial":"|NM_METAL"}, {"selfCollision":false}, {"collision":true} {"group":"etki_radiator"}, {"nodeWeight":2.7}, {"engineGroup":"radiator"} {"chemEnergy":200,"burnRate":0.4"flashPoint":250,"specHeat":0.8,"smokePoint":150,"selfIgnitionCoef":false}, ["rad1", 0.0, -1.8, 0.7], {"chemEnergy":false,"burnRate":false,"flashPoint":false,"specHeat":false,"smokePoint":false,"selfIgnitionCoef":false}, ["rad2", 0.0, -1.8, 0.3], {"engineGroup":""} {"group":""}, ], "beams": [ ["id1:", "id2:"], {"beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, {"beamSpring":1000000,"beamDamp":150}, {"beamDeform":7500,"beamStrength":"FLT_MAX"}, {"deformGroup":"radiator_damage","deformationTriggerRatio":0.05} //radiator {"deformLimitExpansion":""}, ["rad2", "rad1"], ["rad1", "f15"], ["rad1", "f15r"], ["rad1", "f13rr"], ["rad1", "f11rr"], ["rad1", "f15l"], ["rad1", "f13ll"], ["rad1", "f11ll"], ["rad2", "f11"], ["rad2", "f11ll"], ["rad2", "f11rr"], ["rad2", "f13ll"], ["rad2", "f13rr"], //to engine {"beamSpring":14000,"beamDamp":300}, {"beamDeform":1450,"beamStrength":3600}, {"optional":true} //duplicate beams for better flexbody breaking ["rad1","e4r"], ["rad1","e4l"], ["rad1","e4r"], ["rad1","e4l"], //tube ["rad2","e4l"], {"optional":false} {"deformGroup":""} {"beamPrecompression":1, "beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, ], } "etki_radiator_race_thermod": { "information":{ "authors":"BeamNG", "name":"High Performance Radiator(thermostat mod)", "value":270, } "slotType" : "etki_radiator", "flexbodies": [ ["mesh", "[group]:", "nonFlexMaterials"], ["etki_radtube", ["etki_engine","etki_radiator"]], ["etki_radiator", ["etki_radiator"]], ], "mainEngine":{ "radiatorArea":0.34, "radiatorEffectiveness":13000, "coolantVolume":9, "radiatorFanType":"electric", "radiatorFanTemperature":100, "radiatorFanMaxAirSpeed":3, "thermostatTemperature":80, "thermostatRange":20, }, "nodes": [ ["id", "posX", "posY", "posZ"], //radiator {"frictionCoef":0.5}, {"nodeMaterial":"|NM_METAL"}, {"selfCollision":false}, {"collision":true} {"group":"etki_radiator"}, {"nodeWeight":2.7}, {"engineGroup":"radiator"} {"chemEnergy":200,"burnRate":0.4"flashPoint":250,"specHeat":0.8,"smokePoint":150,"selfIgnitionCoef":false}, ["rad1", 0.0, -1.8, 0.7], {"chemEnergy":false,"burnRate":false,"flashPoint":false,"specHeat":false,"smokePoint":false,"selfIgnitionCoef":false}, ["rad2", 0.0, -1.8, 0.3], {"engineGroup":""} {"group":""}, ], "beams": [ ["id1:", "id2:"], {"beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, {"beamSpring":1000000,"beamDamp":150}, {"beamDeform":7500,"beamStrength":"FLT_MAX"}, {"deformGroup":"radiator_damage","deformationTriggerRatio":0.05} //radiator {"deformLimitExpansion":""}, ["rad2", "rad1"], ["rad1", "f15"], ["rad1", "f15r"], ["rad1", "f13rr"], ["rad1", "f11rr"], ["rad1", "f15l"], ["rad1", "f13ll"], ["rad1", "f11ll"], ["rad2", "f11"], ["rad2", "f11ll"], ["rad2", "f11rr"], ["rad2", "f13ll"], ["rad2", "f13rr"], //to engine {"beamSpring":14000,"beamDamp":300}, {"beamDeform":1450,"beamStrength":3600}, {"optional":true} //duplicate beams for better flexbody breaking ["rad1","e4r"], ["rad1","e4l"], ["rad1","e4r"], ["rad1","e4l"], //tube ["rad2","e4l"], {"optional":false} {"deformGroup":""} {"beamPrecompression":1, "beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, ], } } Then select the mod radiator And it works as shown