Two-stroke oil (also referred to as two-cycle oil, 2-cycle oil, 2T oil, 2-stroke oil or petroil) is a special type of motor oil intended for use in crankcase compression two-stroke engines.omparing regular lubricating oil with two-stroke oil, the relevant difference is that two-stroke oil must have a much lower ash content. This is required to minimize deposits that tend to form if ash is present in the oil which is burned in the engine's combustion chamber.