Types of Engines You Wouldn’t Find in Electric Vehicles

Tim Jumah

With the ever-increasing popularity of electric vehicles (EVs), it can be easy to overlook the wide range of traditional engines that have powered cars for decades. From the basic internal combustion engine to elaborate rotary engines, the energy sources for vehicles have diversified tremendously over time. While EVs dominate headlines, exploring the unconventional engines not found in electric vehicles can provide a fascinating glimpse into automotive history and innovation. In this article, we will closely examine some of these unique engines and their notable features.

The Internal Combustion Engine

The internal combustion engine (ICE) is undoubtedly one of the most widely recognized automobile engines. Its operation revolves around burning fuel internally to create motion through controlled explosions within cylinders. This engine type generally relies on gasoline or diesel as fuel sources and has been refined over many decades to maximize efficiency and power output.


  • Vast network for refueling: Traditional engines have an advantage over electric vehicles regarding refueling infrastructure.
  • Long driving range: Gasoline or diesel-powered vehicles typically boast a longer driving range than electric vehicles, making them suitable for long journeys without frequent recharging intervals.
  • Rapid refueling: Refilling a fuel tank typically takes only a few minutes compared to charging an electric vehicle battery, which can take significantly longer.


  • Environmental impact: Internal combustion engines emit air pollutants, including carbon dioxide, nitrogen oxides, and particulate matter.
  • Dependence on fossil fuels: Traditional engines rely heavily on non-renewable fuels, contributing to resource depletion and climate change concerns.
  • Complex maintenance: ICEs often require regular maintenance, including oil changes, filter replacements, and system checks.

The Rotary Engine

The rotary engine, also known as the Wankel engine, is an unconventional design with rotors instead of pistons. Invented by German engineer Felix Wankel in the 1950s, this engine eliminates the need for reciprocating linear motion and offers a higher power-to-weight ratio than traditional piston engines.


  • Compact design: The rotary engine’s compact size allows for more flexibility in vehicle design and can often fit into smaller spaces.
  • High-revving capabilities: Rotary engines can rev to extremely high rpm levels, providing exhilarating performance in certain applications.
  • Smooth operation: Due to its unique design, rotary engines operate with fewer vibrations than traditional piston engines, lending itself to a smoother ride experience.


  • Fuel consumption and emissions: Rotary engines tend to consume more fuel and emit higher levels of hydrocarbons than their piston counterparts.
  • Limited torque at low rpm: Rotary engines typically lack low-end torque, making them less suitable for heavy-duty or towing applications.
  • Oil consumption: The design of the rotary engine often leads to higher oil consumption than conventional engines.

The Steam Engine

The steam engine is a historic engine that revolutionized transportation during the Industrial Revolution. While rarely found in modern vehicles, it played a crucial role in shaping the automotive industry by proving the concept of harnessing external energy sources for propulsion. Steam engines convert heat energy from burning fuel into mechanical energy through steam pressure.


  • Efficiency at constant speeds: Steam engines produce continuous power outputs over extended periods, making them ideal for applications requiring consistent speeds, such as trains or boats.
  • The versatility of fuel options: Steam engines can run on various fuels, including coal, wood, natural gas, or even nuclear reactors if designed accordingly.
  • Thermal mass advantage: Once heated up, steam engines maintain thermal energy well even with the heat source turned off, allowing for controlled cooling and reheating as needed.


  • Slow startup time: Steam engines take considerable time to heat up and generate sufficient steam pressure, resulting in longer startup times than other engine types.
  • Bulkiness and weight: Steam engines tend to be significantly larger and heavier than internal combustion engines, making them less practical for modern vehicles.
  • Limited efficiency at varying speeds: Steam engines exhibit poor efficiency due to throttle control complexities.

The Stirling Engine

The Stirling engine is an external combustion engine based on temperature differentials. Reverend Robert Stirling invented this unique engine design in the early 19th century and aims to improve energy efficiency by utilizing hot and cold air differentials to drive pistons.


  • Quiet operation: The Stirling engine runs quietly compared to traditional piston engines due to its external combustion process and absence of noisy exhaust valves.
  • Flexibility in fuel options: This engine type can run on various fuels, including natural gas, biomass, or even solar power.
  • High theoretical efficiency: The Stirling engine has the potential for high theoretical efficiency due to the complete regenerative cycle it undergoes.


  • Low power-to-weight ratio: The Stirling engine generally has a lower power-to-weight ratio than internal combustion engines.
  • Slow response time: Due to its design characteristics, the Stirling engine tends to have slower response times than traditional piston engines.
  • Complex engineering requirements: Building a highly efficient Stirling engine requires meticulous attention to detail, often demanding advanced engineering techniques.

The Gas Turbine Engine

Gas turbine engines, also known as jet engines, are primarily associated with aircraft propulsion but have also found their way into other applications, such as tanks and trains. These engines operate on the principle of compressing air, adding fuel, and igniting it to produce high-velocity exhaust gases that create thrust.


  • High power-to-weight ratio: Gas turbines achieve impressive power-to-weight ratios, making them perfect for applications where weight is critical, such as aircraft.
  • Immediate power availability: Unlike internal combustion engines that require a warm-up period, gas turbines can provide immediate power upon startup.
  • Low vibration levels: Gas turbine engines operate with minimal vibration due to their balanced design and rotating components.


  • Lower efficiency compared to other engines: Gas turbine engines tend to have lower thermal efficiencies than internal combustion engines, especially at partial loads.
  • High operating temperatures: The high operating temperatures of gas turbine engines often necessitate advanced cooling systems and exotic materials for proper operation.
  • Complex maintenance and repair: Due to their intricate design and reliance on precision equipment, gas turbine engines require specialized maintenance procedures and technicians.


While electric vehicles may be capturing the spotlight in the automotive industry today, it is important not to forget the diverse range of traditional engines that have powered vehicles for generations. Each engine type offers advantages and disadvantages, from the reliable internal combustion engine to the innovative rotary engine. The rich history of engine development showcases the continuous pursuit of efficiency and performance in transportation. As technology advances and energy sources change, who knows what new types of engines we may find in vehicles in the future?

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Jumah has been a content writer for business and technology topics since early 2019. He has experience in writing and marketing and is dedicated to creating informative and engaging content.
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