standard oil used for the 3.5 High Output engine is 10w40.
Thereis a tag on the filler plug for the differential. On my 2001 300M the tag ready 80 to90 wt hypoid gear oil only.
Next to the oil filter - closer to the front of the car
Just behind the Oil Dipstick
5w30
lucas oil
Can be the level is low or the sensor is going back.
I recommend going to this site for all your Chrysler 300m questions. www.lhforums.com Any name brand 5w30
5W-30 Synthetic Oil.
5w30
Right hand. Turn counterclockwise to loosen.
The thermostat should be where the bottom hose of the radiator is conected to the motor, next to the oil filter..
5w30 is recommended but 10w30 can be used.