Introduction:
Trucks and buses are commercial vehicles and use multi cylinder diesel engines.
Reasons for using:
1. A multicylinder engine develops more power. A commercial vehicle needs greater force to propel the vehicle because it carries greater loads.
2. A diesel engine runs at a higher compression ratio and at this compression ratio the thermal efficiency of a multi-cylinder engine is higher than an Otto cycle petrol engine. This means that a diesel engine gives better fuel economy per kilometer.
3. A multi cylinder engine has a greater swept volume and also its surface volume ratio is increased. This results in greater engine output and also better cooling which is essential for the protection of the engine parts like cylinder head, cylinder liner, piston, etc. The lubricating oil is also prevented from partial oxidation.
4. In a multi-cylinder engine, vibrations are decreased due to balancing of the crank.
