A tank truck or tanker truck (United States usage) or

A tank truck or tanker truck (United States usage) or tanker (United Kingdom usage), is a motor vehicle designed to carry liquefied loads, dry bulk cargo or gases on roads. The largest such vehicles are similar to railroad tank cars which are also designed to carry liquefied loads. Many variants exist due to the wide variety of liquids that can be transported. Tank trucks tend to be large; they may be insulated or non-insulated; pressurized or non-pressurized; and designed for single or multiple loads (often by means of internal divisions in their tank). Some are semi-trailer trucks. They are difficult to drive due to their high center of gravity.

Size and volume
Tank trucks are described by their size or volume capacity. Large trucks typically have capacities ranging from 5,500 to 11,600 US gallons (20,800 to 43,900 L; 4,580 to 9,660 imp gal). In Australia, road trains up to four trailers in length (known as Quad tankers) carry loads in excess of 120,000 L. Longer road trains transporting liquids are also in use.