How come my remote controlled vehicle is delayed?

So I made a car completely using joints and constraints. However, I noticed that in order to operate like a car, I must make a script that operated the joints:

local seat = script.Parent
local car = workspace:FindFirstChild("Car_"..script.Parent.Owner.Value)

local function onChanged(property)
	if property == "Steer" then
		local SteerAngle = car.SteerAngle.Value
		car.Angle.Value = seat.Steer*SteerAngle
	end
	if property == "Throttle" then
		local MaxSpeed = car.MaxSpeed.Value
		car.Speed.Value = seat.Throttle*MaxSpeed
	end
end

and another one to manages those values:

while wait() do
	local car = script.Parent
	local seat = script.Parent.Seat.Value
	local speed = car.Speed.Value
	local angle = car.Angle.Value
	script.Parent:FindFirstChild("FR").HingeConstraint.AngularVelocity = speed*seat.Throttle*-1
	script.Parent:FindFirstChild("RR").HingeConstraint.AngularVelocity = speed*seat.Throttle*-1
	script.Parent:FindFirstChild("FL").HingeConstraint.AngularVelocity = speed*seat.Throttle
	script.Parent:FindFirstChild("RL").HingeConstraint.AngularVelocity = speed*seat.Throttle
	script.Parent:FindFirstChild("Chassis").HingeConstraint.TargetAngle = angle*seat.Steer
end

I am wondering why the motors are so delayed in functioning... On play solo, they work just fine, but on a test server, they are delayed by around 0.5 of a second.

Help would be much appreciated. Thanks in advance!

If this works on solo well but on a test server not as much you could be a victim of latency.

Ping and latency (same thing) are the milliseconds it takes to travel from Server:Client. If I'm not mistaken it's virtually reproduced even in ROBLOX Test servers. There are a multitudes of ways you could avoid this, to some limits. One of these would be to use a local script, which, as you can imagine, can lead to security issues but typically, are fine for most players.