Fuel efficiency: fuel efficiency tends to be slightly lower when using biodiesel due to the lower energy content of the fuel. Typically, the drop-off is in the same range as the reduction in peak engine power (3-5 percent). Engine wear: short-term engine wear when using biodiesel has been measured to be less than that of petroleum diesel.
An important difference between the two engines is the thermal efficiency of diesel engines. Thermal efficiency refers to the work that can be expected to be produced by the engine's fuel. A gas engine is about 20 percent less thermal efficient than a diesel engine. This means that a diesel engine has a 20 percent increase in its fuel economy.
Keeping It Simple. A diesel engine takes a very simple and direct approach to internal combustion. Its design involves compressing the air as much as 2-1/2 times more than a gasoline engine. Compression causes heat. So when the fuel is delivered, through a high-pressure fuel injection system, to the compressed air, the heat, which can reach as
The turboprop uses a gas turbine core to turn a propeller. As mentioned on a previous page, propeller engines develop thrust by moving a large mass of air through a small change in velocity. Propellers are very efficient and can use nearly any kind of engine to turn the prop (including humans!). In the turboprop, a gas turbine core is used.

Engine. An animation showing the four stages of the four-stroke gasoline-fueled internal combustion cycle with electrical ignition source: Induction (Fuel enters) Compression. Ignition (Fuel is burnt) Emission (Exhaust out) Jet engines use the heat of combustion to generate a high-velocity exhaust as a form of reaction engine.

The economic argument. A big part of the diesel engine vs petrol engine comparison is the fuel-efficiency figures. Diesels are simply better in this department, as much as 30 or even 40 per cent better, although modern, direct-injection petrol engines are catching up. VUUXZ. 647 547 948 638 206 646 972 108

how does a diesel engine work vs gas