See also:

What to Use
Refer to Recommended Fluids and Lubricants   to determine what kind of lubricant to use. ...

Passing
More passing distance is needed when towing a trailer. Because the rig is longer, it is necessary to go much farther beyond the passed vehicle before returning to the lane. ...

Weight of the Trailer
How heavy can a trailer safely be? It should never weigh more than 450 kg (1,000 lbs). But even that can be too heavy. Speed, altitude, road grades, outside temperature, special equipment, ...