Is there such a thing as v4 mustang?

No, there is no Mustang model officially designated as a "V4". The Ford Mustang has had numerous generations, typically denoted by Roman numerals (I, II, III, IV, V, VI, VII), but never a V4. The engine options have varied across generations, including V6, V8, and even four-cylinder engines, but the car itself is not identified by a "V4" designation.