Mules are slightly smaller than their horse parent, and when they grow they share traits of both a donkey (the long ears), and the horse (color, tail, etc.). A Mule in the grass.
For example, a 2014 Ford F-150 is considered a half ton truck but most variants can carry a lot more than 1,000 pounds in the bed. Since these terms are probably not going away any time soon, it's best just to think of them as smaller, mediumest, and more than medium.. (Pause for laughter).
A single vehicle with a GVWR of 10,000 lbs. or less including a tow dolly, if used. If the towing vehicle weighs 4,000 lbs. or more unladen, you may tow a: Trailer coach not exceeding 9,000 lbs. gross. Trailer coach or 5th-wheel travel trailer under 10,000 lbs. GVWR when towing is not for compensation. 5th-wheel travel trailer exceeding 10,000 lbs. but not exceeding 15,000 lbs.