There are two types of engines found in nearly every car and truck on the road. They used what is called four strokes reciprocating internal combustion engine which is a high horse powered type of engine. Both gas and diesel engines use this type of application. A third type called a two stroke engine, found in lower powered applications such as:

  • Lawn and garden equipment
  • Dirt bikes
  • Mopeds
  • Jet skis
  • Small outboard motors
  • Radio controlled model planes
  • Chain saws and jet skies

Advantages of two stroke engines

  • Two stroke engines do not have valves which are easy to construct and lowers their weight
  • Two stroke engines fire once every revolution while four stroke every other revolution,
  • this two stroke engines lower output in horse power
  • Two stroke engines can work in any position, since oil flow is not a concern with any valves to worry about.

Disadvantages of two stroke engines

  • Two stroke engines do not last as long as four stroke engines; there is no lubrication system in a two stroke engine so parts wear out a lot faster.
  • Two stroke oil is expensive; you would burn a gallon every 1000 miles if it were in a car
  • Two stroke engines use more fuel
  • Two stroke engines produce a lot of pollution, and the way the engine is designed that part of the air/fuel leaks out of the chamber through the exhaust port, which is why you see a small thin film, or sheen, of oil around any two stroke outboard motor, and this leaking oil is a real mess for the environment. This is the reason why two stroke engines are used only in application where the motor is not used very often and a fantastic power-to-weigh ratio is important.
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William Anderson (Schoolworkhelper Editorial Team)
William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0


  1. Basically all of the disadvantages you list are only true of two stroke engines which are designed to be as small and simple as possible. Two stroke engines can be lubricated just as four stroke engines and so can last longer than you suggest and may not just burn oil.
    Two stroke engines can be designed to operate more efficiently from a thermodynamic perspective than a four stroke engine and if properly designed air/fuel mixture does not leak in significant amounts from the exhaust.

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