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What are the percentages of energy efficiency in diesel and petrol engines?
Wiki User
∙ 14y ago
About 39 per cent. The Gibbs free energy for gasoline (petrol) is about 45.7 MJ/Kg, and the amount of mechanical energy obtained is about 17.6 MJ/Kg. The figures will vary a bit from one engine to another, and from one grade of fuel to another.
(from Wikipedia)
Wiki User
∙ 15y ago
Wiki User
∙ 14y ago.0005962
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Are diesel engines more polluted than steam engines?
Of an individual diesel engine and an individual steam engine of the same energy output the diesel engine would be less polluting. It is far more efficient. However, there are far more diesel engines than steam engines in the world today so overall diesel engines pollute more than steam engines.
Why petrol engines are faster than diesel engines?
Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way. Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way.
How do engines lose energy to the environment?
Mainly through the relatively low thermodynamic efficiency of heat engines (petrol, diesel, steam turbines, gas turbines), which waste at least 50% of the chemical energy of the fuel. Engineers know that the efficiency is set by the upper and lower temperatures of the working fluid in the engine. They also understand the limitations of the materials available to make machines, which place limits on the temperatures and pressures that can be used.
What is the ratio of the energy a machine delivers to the energy supplied to it?
efficiencyThe ratio of useful energy to total input energy is called efficiency. It refers to the percentage of the work input that is converted to work output.
How can you calculate the efficiency of an appliance in terms of power?
vague question. Efficiency in terms of energy = useful energy/total energy x 100 vague question. Efficiency in terms of energy = useful energy/total energy x 100
Why are diesel engines loud?
Diesel engines detonate. Diesel has more potential energy than gasoline, instead of burning evenly, diesel explodes creating a knock or rattle noise.
Why do diesel engines have more torque than gas engines?
Engines with longer piston stroke, higher turbo boost pressures, and diesel fuel has more energy in it than gasoline.
Diesel fuel is used in the engines of the machines and trucks at the quarry Which of these is the main energy transformation as the fuel is used by the engines?
Chemical energy is converted to kinetic energy.
What energy source can you use in cars?
Internal combustion gasoline, propane, or diesel engines. Electric motors. Steam engines, fuel cell engines are examples of energy sources.
Are diesel engines more polluted than steam engines?
Of an individual diesel engine and an individual steam engine of the same energy output the diesel engine would be less polluting. It is far more efficient. However, there are far more diesel engines than steam engines in the world today so overall diesel engines pollute more than steam engines.
Are gasoline and Diesel engines heat engines?
Yes, gasoline and diesel engines are heat engines. The energy released by the burning fuel causes the gas in the cylinders to expand and push the pistons, which in turn do work.
Has diesel got more fuel energy than petrol?
Actually diesel fuel has a slightly lower amount of energy per weight than gasoline (45.3 vs. 47.2 MJ/kg). Cylinder pressure is what gives diesel engines their power, that is why diesel engines parts are so much stronger/heavier than gas similar sized gas engines.
Why do diesel engines give more mileage than petrol engines?
1) Diesel contains more energy in it than Petrol 2) Diesel engines can run much leaner air fuel ratios than petrol without engine damage, due to compression ignition there are no pre-ignition problems 3) Pumping losses are much lower because the throttle is always wide open 4) Compression ratio is much higher which leads to better thermal efficiency than petrol.
Machine that transforms heat into mechanical energy?
A ficticious heat engine that works at the maximum theoretical efficiency is called a Carnot engine. Real engines, that obviously work at a lesser efficiency, include the combustion engines found in cars.A ficticious heat engine that works at the maximum theoretical efficiency is called a Carnot engine. Real engines, that obviously work at a lesser efficiency, include the combustion engines found in cars.A ficticious heat engine that works at the maximum theoretical efficiency is called a Carnot engine. Real engines, that obviously work at a lesser efficiency, include the combustion engines found in cars.A ficticious heat engine that works at the maximum theoretical efficiency is called a Carnot engine. Real engines, that obviously work at a lesser efficiency, include the combustion engines found in cars.
What are the feature of good engine?
A good engine is an efficient one. An engine converts energy in one form to energy in another form. How fast that happens is measured by the power. If a joule of energy is converted every second, that is a power of 1 watt. If you measure the power of the energy put into the engine, and the power coming out, then divide one into the other, that is called the efficiency, usually a percentage. A perfect engine has 100% efficiency. All practical engines have less than 100% efficiency, so less comes out than went in. For that reason engines get warm or hot on the wasted energy. Examples of efficiency: Electric motor or generator 90-98% Steam or gas turbine 20-50% Diesel or petrol engine 20-25%
The Pros of Diesel Engines?
Car engines come in two broad categories, both named after the type of fuel they consume: gasoline and diesel. In turn, the design of each engine is named after their inventors: Nikolaus Otto invented the Otto cycle for gasoline engines, and Rudolf Diesel invented the Diesel cycle for diesel engines. Diesel created his engine after learning about the engine created by Otto at the Polytechnic High School, the equivalent of an engineering college. Gasoline engines are less efficient than diesel, but diesel has a reputation for being dirtier than gasoline, so gasoline is the engine of choice for most domestic automobile manufacturers. Despite the fact that they are both internal combustion engines, the disadvantages of diesel has in the past far outweighed the advantages. Fortunately, improvements in design have made diesel more attractive, and diesel today is a serious alternative to the predominant gasoline engine. Major car makers like Mercedes-Benz incorporated diesel engines into their designs in the past, but today the diesel engine is starting to make credible inroads with other companies. The main advantage of a diesel engine is it's high fuel economy. The fuel economy of a diesel-powered truck or car is about twenty to thirty percent better than gasoline-powered vehicles. In times of high fuel prices, this can prove a big enough advantage to choose diesel by itself. Other advantages include less maintenance costs, due to the absence of spark plugs. The Diesel cycle uses the intense compression of fuel and air to ignite and combust the mixture. The reason this works is because of the high energy density of diesel fuel. The high energy density combined with the increased mechanical efficiency explains why diesel engines achieve such incredible fuel efficiency. Added advantages include improvements such as less noise, less soot and less cost. Today, the noise produced from a diesel engine and a gasoline engine are so close they are almost indistinguishable. Owners of diesel engines tend to fall in love and spread the word about how efficient and clean their cars are.
Why isn't it possible to attain an efficiency of 100 percent in heat engines?
Because unavoidably there would be a loss of energy during the process
