See also:

Weight of the Trailer
How heavy can a trailer safely be? It should never weigh more than 1,000 lbs (454 kg). But even that can be too heavy. It depends on how the rig is used. For example, speed, altitude, road grade ...

Engine Oil Additives
Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM Standard GM6094M are all you will need for good performance and engine protection. ...

When to Inspect the Engine Air Cleaner/Filter
Inspect the air cleaner/filter at the scheduled maintenance intervals and replace it at the first oil change after each 80 000 km (50,000 mi) interval. See Maintenance Schedule  for more info ...