Check your vehicle manual?...or was it purchased used without one? Most newer models call for 5w30 average.
may need an oil pump may need a motor
5w30
if you dont have any oil in the cars motor that would be a reasin why its knocking
5w305w30
What it says in the manual
you should but a couple corts of royal purple motor oil
5W-30
The Polaris 400 Sport can use any as a be certified motor oil. The manufacturer recommends a 10W-30 motor oil.
motor oil
Any kind of name brand 10w-30 oil should work just fine.
I use Syntec 5W40 in mine.
It depends the motor.