Diesel Engine vs Gasoline Engine – Difference and Comparison

What is Diesel Engine?

A diesel engine is a combustion engine that runs on diesel fuel. Diesel engines are more fuel efficient than gasoline engines due to their higher compression ratio and use of direct injection.

Diesel engines are also more potent, producing more torque at lower speeds. This makes them ideal for trucks, buses, and other heavy-duty applications.

Diesel engines are also more reliable, as they require less maintenance and can run longer without service.

Diesel engines have become increasingly popular in passenger vehicles due to their fuel efficiency and lower emissions. Diesel engines are four-stroke engines, which utilize four processes to generate power.

diesel engines use direct injection, meaning fuel is injected directly into the cylinder, allowing for more efficient combustion. Diesel engines are more fuel efficient, robust, and reliable than gasoline engines. However, they are more expensive to purchase and maintain and can produce higher emissions. diesel fuel can be more expensive than gasoline in some areas. As a result, diesel engines are best suited for heavy-duty applications such as trucks and buses, where the increased efficiency and power can be utilized.

What is Gasoline Engine?

A gasoline engine is a combustion engine that runs on gasoline as its fuel. The term gasoline engine is used to refer to a spark-ignition engine used in most cars and trucks today. Gasoline engines can also refer to compression-ignition engines used in diesel vehicles.

Gasoline engines work by igniting fuel and air in the engine’s combustion chamber. The fuel and air are mixed and then compressed by a piston. When it reaches the top of its travel, a spark is created by the spark plug, which ignites the fuel and air mixture. The heat from the combustion causes the piston to move down, which creates the power to turn the engine’s crankshaft.

Gasoline engines offer several advantages over other types of internal combustion engines. They are lighter and more efficient than diesel engines and can produce more power than gasoline engines. gasoline engines are more reliable and require less maintenance than diesel engines.

Gasoline engines can be found in various applications, from cars and trucks to boats and motorcycles. They are also used in stationary applications, such as generators and lawnmowers.

Difference Between Diesel Engines and Gasoline Engines

  1. Diesel engines are more efficient and have a higher compression ratio than gasoline engines. 
  2. Diesel engines can produce higher torque at lower RPMs than gasoline engines.
  3. Diesel fuel is denser than gasoline, so more energy is obtained from the same fuel volume.
  4. Diesel engines require an extended cranking period, while gasoline engines start quickly.
  5. Diesel engines are heavier than gasoline engines due to their higher compression ratio and more significant internal components.
  6. In gasoline engines, a spark ignites the fuel-air mixture, while in diesel engines, the fuel-air mixture is ignited by the heat of compression.
  7. Gasoline engines use a fuel mixture of gasoline and air for combustion, while diesel engines use a fuel mixture of diesel and air.
  8. Diesel engines have a higher power output than gasoline engines.

Comparison Between Diesel Engine and Gasoline Engine

Parameters of ComparisonDiesel EngineGasoline Engine
Ignition SystemDiesel engine use compression ignitionGasoline engines use spark ignition
FuelDiesel engines use diesel fuelGasoline engines use gasoline fuel  
EfficiencyThe diesel engine is more efficientGasoline engines are less efficient than diesel engines
PriceDiesel engine is expensiveGasoline engines are priced moderately
SmellThe diesel engine produces a unique smellGasoline engines do not produce a unique smell


  1. Supplemental Materials for Carcinogenicity of diesel-engine and gasoline-engine exhausts and some nitroarenes – The Lancet Oncology
  2. WHOLIS-Diesel and gasoline engine exhausts and some nitroarenes (bireme.br)