M_boy

Why are diesel engines  not preferred in commercial ? 1. Diesel engines, beca use they have much higher compression ratios (20:1 for a typical diesel  vs. 8:1 for a typical gasoline engine), it  tend to be heavier than an equivalent gasoline engine. 2. Diesel engines also tend to be more expensive. 3. Diesel engines, because of the weight and compression ratio, tend to have lower maximum  RPM ranges than gasoline engines .This makes diesel engines high  torque rather than high  horse  power, and that tends to make diesel cars slow in terms of acceleration.  4. Diesel engines must be fuel injected, and in the past fuel injection was expensive and less  reliable. 5. Diesel engines tend to produce more smoke. 6. Diesel  engines are harder to start in cold weather, and if they contain glow plugs, diesel  engines can require you to wait before starting the engine so the glow plugs can...

   Exhaust Gas Recirculation or EGR system: The Exhaust Gas Recirculation or EGR system is one of several vehicle emission control systems. It helps reduce the amount of the nitrogen oxides (NOx) in the exhaust gases. Nitrogen oxides are normally formed in the process of combustion in the engine cylinders. EGR system. Click for a  larger image . However, their formation increases dramatically at higher combustion temperatures (above 1600 °C or 2912 °F). The EGR system reduces the combustion temperature by diverting a small portion of the exhaust gases back into the intake manifold. How does it work?  Exhaust gases are no longer combustible. Diluting the intake air with exhaust gases makes the air/fuel charge less combustible. Not all vehicles are equipped with an EGR system; many newer cars utilize a variable valve timing and other means to control the combustion temperatures and NOx emissions. The majority of modern diesel vehicles incorporate EGR valves into their ...