Read newer engines have closer tolerances!

 

 

Oil light come on at 6psi oil pressure or below and lighter weight oil can cause it to come on if there is a problem developing i.e. low pressure - sooner than heavier weight oil. If it come on under load at rpms above an idle I would be concerned if it is from low pressure and not a loose sensor wire. Keep your ears open for engine knocking noises - sign of low pressure especially at startup or idle when engine is hot.