390.3 General applicability
b) The rules in Part 383, Commercial Driver’s License Standards; Requirements and Penalties, are applicable to every person who operates a commercial motor vehicle, as defined in §383.5 of this subchapter, in interstate or intrastate commerce and to all employers of such persons.
f) Exceptions. Unless otherwise specifically provided, the rules in this subchapter do not apply to—
(f)(3) The occasional transportation of personal property by individuals not for compensation nor in the furtherance of a commercial enterprise;
§383.91 Commercial motor vehicle groups.
(a) Vehicle group descriptions. Each driver applicant must possess and be tested on his/her knowledge and skills, described in subpart G of this part, for the commercial motor vehicle group(s) for which he/she desires a CDL. The commercial motor vehicle groups are as follows:
(a)(1) Combination vehicle (Group A)—Any combination of vehicles with a gross combination weight rating (GCWR) of 11,794 kilograms or more (26,001 pounds or more) provided the GVWR of the vehicle(s) being towed is in excess of 4,536 kilograms (10,000 pounds).
(a)(2) Heavy Straight Vehicle (Group B)—Any single vehicle with a GVWR of 11,794 kilograms or more (26,001 pounds or more), or any such vehicle towing a vehicle not in excess of 4,536 kilograms (10,000 pounds) GVWR.
(a)(3) Small Vehicle (Group C)—Any single vehicle, or combination of vehicles, that meets neither the definition of Group A nor that of Group B as contained in this section, but that either is designed to transport 16 or more passengers including the driver, or is used in the transportation of materials found to be hazardous for the purposes of the Hazardous Materials Transportation Act and which require the motor vehicle to be placarded under the Hazardous Materials Regulations (49 CFR part 172, subpart F).
383.5 Definitions.
Commercial motor vehicle (CMV) means a motor vehicle or combination of motor vehicles used in commerce to transport passengers or property if the motor vehicle—
(a) Has a gross combination weight rating of 11,794 kilograms or more (26,001 pounds or more) inclusive of a towed unit(s) with a gross vehicle weight rating of more than 4,536 kilograms (10,000 pounds); or
(b) Has a gross vehicle weight rating of 11,794 or more kilograms (26,001 pounds or more); or
(c) Is designed to transport 16 or more passengers, including the driver; or
(d) Is of any size and is used in the transportation of hazardous materials as defined in this section.
Clear as Mud........
The short, unless you are doing business or transporting HAZMAT, your F150 / 250 / 350 is fine for personal use towing. That is how Uhaul can rent a 28 foot truck and a full car trailer to the average Joe.
Exception of NY City
What constitutes a "truck" in New York City?
Pursuant to Section 4-13 of the New York City Traffic Rules, a truck is defined as any vehicle or combination of vehicles designed for the transportation of property that has the following characteristics:
two axles and six tires, or;
three or more axles
For the purposes other than parking, stopping and standing rules, a vehicle designed, maintained, or used primarily for the transportation of property or for the provision of commercial services and bearing commercial plates is considered a commercial vehicle.
Vehicles from other states or countries bearing commercial or equivalent registration plates from other states or countries shall not be deemed trucks or commercial vehicles unless they are permanently altered and marked as required in the above bulleted list.
You got to read from top down and watch for the exceptions. 6/7 years of decifering for my company's employee shuttles.