A tanker, gas truck, fuel truck, or tanker truck (United States use) or tanker (UK use) is a motor vehicle designed to transport liquids or gas on roads. Such large vehicles are also similar to railway tank cars designed to transport liquid cargoes. Many variants are available due to the wide variety of liquids that can be transported. Tank trucks tend to be large; they can be insulated or not insulated; pressurized or unpressurized; and designed for single or multiple loads (usually through internal compartments in their tanks). Some of them are trucks with semi-trailers. Due to their high center of gravity and the potential free surface effect of agitated liquids in a partially filled tank, they are difficult to drive and highly susceptible to tipping.

Prior to tank distribution, oil was delivered in cans. [2] It was distributed in tanks hauled by horses from the 1880s. [3] In 1910 Standard Oil began using motor tankers. [4] Anglo American Oil introduced underground tanks and distribution tankers to Britain in 1920. [5] Pickfords took over an oil tanker company in 1921 and soon became the owner of 1,000 British gallons (4,500 l; 1,200 US gallons) of 3,600 imp gallons. (16,000 l; 4,300 US gallons) by the mid-1930s. [6] Development was slower elsewhere. For example, the first oil tanker (200 imp gal (910 l; 240 US gal)) from Auckland [7] to arrive in Hamilton, New Zealand, was greeted by a band in 1927.