Some modern diesel engines are starting to come out with electronically controlled injection pumps, but the vast majority of them out there have purely mechanical pumps。 No electricity is required to make a diesel engine run, except for a simple fuel cut off solenoid so that you can hut the engine down。
Turbo-charging a diesel is easier than turbo-charging a gasoline engine。 One problem for a gasoline engine is that if the compression ratio is too high, and the pressure in the cylinder gets too high during the inlet stroke, then the fuel/air mixture can start to burn too soon, while the piston is still on the way up。 A turbo increases the pressure in the cylinder making this problem worse。 With a diesel engine, there is no fuel in the cylinder during the compression stroke, so a turbo can be used to pack as much air in there as desired without causing problems。
The process of starting a diesel engine is less affected by temperature。 When a gasoline engine is started from cold it needs a lot of fuel to make it run properly。 If you do short trips all the time then you'll get far below the fuel economy that you'd normally get。 Since emissions are proportional to the amount of fuel consumed, you'll be producing higher pollution levels。 Diesel engines are ideal for short journeys because their efficiency is almost as high cold as when they are hot。
Diesel engines last a lot longer than gasoline engines。 This is because gasoline destroys lubrication and diesel fuel doesn't。 Cold start-ups are a real killer for gasoline engines because of all that extra gasoline needed to start a cold engine。
A compression ratio of 19:1 to 25:1 gives significant engine braking, but it also makes the engine hard to start。 You'll need a good battery, one of very high amperage, and starter motor。
Glow plugs are needed。 Diesel engines rely on the heat of compressed air to ignite their fuel。 When the engine is cold, compression alone may not produce enough heat for the fuel to burn, so most car and truck diesels use glow plugs, electric elements that heat up the cylinder before a cold engine is started These electric heaters are switched on for anywhere from 5 to 10 seconds to make the engine easier to start。 They use about 15 amps each (you have one for each cylinder)。 This is why you need a high amperage battery。 For areas with severe winters, a block heater is a good idea。 Many diesels have them as standard or optional equipment。
Torque is a measure of twisting force, and in the automotive world it translates to the ability to get a load moving。
This makes a diesel engine good for towing, trucks and buses, but will never be great in the 0 to 60 ranges。
Because of their high compression ratios, diesel engines have to be built with more durable components than gasoline engines。 Diesel fuel is a lubricant, and as it is sprayed into the engine during the combustion cycle, it lubricates the cylinder walls。 As a result, diesels are subject to less internal wear than gasoline engines, and will usually run many more miles before requiring an overhaul。 It can make a car more stable, but will handle and corner differentaly than a gasoline engine。 It also makes the steering heavy as well, I would recommend buying a diesel car with power steering。
Diesel engines are nosier than gasoline engines。 If you open the hood of a gasoline car with the engine running, you know that gasoline engines are fairly quiet。 With diesel engines, there's a great deal of mechanical noise, mostly due to the engine's high compression ratios and the fuel injection systems。 They are even nosier when they are cold。
Diesel engines require more frequent routine maintenance than gasoline engines。 On the plus side however, normal gasoline engine maintenance such as replacing the spark plugs, rotor and replacing ignition wires are not necessary on a diesel engine。 You don't have to worry about an Ignition module or coil going bad。 It's simply because a diesel engine has no ignition system。 改善重型SCR系统的应用程序英文文献和中文翻译(7):http://www.youerw.com/fanyi/lunwen_97925.html