Fuel is an important resource used to power many machines and vehicles. The four crossword solutions for the term 'fuel, type of' are PEAT (4 letters), GAS (3 letters), DIESEL (6 letters), and COAL (4 letters). PEAT is a combustible material formed from partially decayed vegetation, which is often used as a fuel in some parts of the world. GAS is a form of fuel made up of hydrocarbons, which is used in many cars and other vehicles. DIESEL is a type of fuel derived from petroleum, which is used in many trucks and other heavy-duty vehicles. COAL is a combustible black or brownish-black sedimentary rock, which is used as a fuel in many countries.