The difference between a gasoline and a diesel engine
\n\u00ac”What is the difference between a\u00a0gasoline\u00a0and a\u00a0diesel engine?”
\nDiesel’s story actually begins with the invention of the\u00a0gasoline engine. Nikolaus August Otto had invented and patented the\u00a0gasoline engine\u00a0by 1876. This invention used the four-stroke combustion principle, also known as the “Otto Cycle,” and it’s the basic premise for most car engines today. In its early stage, the\u00a0gasoline enginewasn’t very efficient, and other major methods of transportation such as the steam engine fared poorly as well. Only about 10 percent of the fuel used in these types of engines actually moved a vehicle. The rest of the fuel simply produced useless heat.
\n\u00acI\u00acn 1878, Rudolf Diesel was attending the Polytechnic High School of Germany (the equivalent of an engineering college) when he learned about the low efficiency of gasoline and steam\u00a0engines. This disturbing information inspired him to create an engine with a higher efficiency, and he devoted much of his time to developing a “Combustion Power Engine.” By 1892 Diesel had obtained a patent for what we now call the\u00a0diesel engine.
\n\u00acIf\u00a0diesel engines\u00a0are so efficient, why don’t we use them more often? You might see the words “diesel engine” and think of big, hefty cargo trucks spewing out black, sooty smoke and creating a loud clattering noise. This negative image of diesel trucks and engines has made diesel less attractive to casual drivers in the United States — although diesel is great for hauling large shipments over long distances, it hasn’t been the best choice for everyday commuters. This is starting to change, however, as people are improving the diesel engine to make it cleaner and less noisy.
\nIf you haven’t already done so, you’ll probably want to read How Car Engines Work first, to get a feel for the basics of internal combustion. But hurry back — in this article, we unlock the secrets of the diesel engine and learn about some new advancements.
\n\u00acIn theory,\u00a0diesel engines\u00a0and\u00a0gasoline engine\u00a0are quite similar. They are both internal combus\u00action engines designed to convert the chemical energy available in fuel into mechanical energy. This mechanical energy moves pistons up and down inside cylinders. The pistons are connected to a crankshaft, and the up-and-down motion of the pistons, known as linear motion, creates the rotary motion needed to turn the wheels of a car forward.
\nBoth\u00a0diesel engines\u00a0and\u00a0gasoline engine\u00a0covert fuel into energy through a series of small explosions or combustions. The major difference between\u00a0diesel engines\u00a0and\u00a0gasoline engine\u00a0is the way these explosions happen. In a\u00a0gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a\u00a0diesel engines, however, the air is compressed first, and then the fuel is injected. Because air heats up when it’s compressed, the fuel ignites.
\nThe following animation shows the diesel cycle in action. You can compare it to the animation of the gasoline engine to see the differences.
\nImage courtesy Baris Mengutay
\nThe\u00a0diesel engines\u00a0uses a four-stroke combustion cycle just like a gasoline engine. The four strokes are:
\n\u2022\u00a0Intake stroke — The intake valve opens up, letting in air and moving the piston down. \u00ac
\n\u2022\u00a0Compression stroke — The piston moves back up and compresses the air.
\n\u2022\u00a0Combustion stroke — As the piston reaches the top, fuel is injected at just the right moment and ignited, forcing the piston back down.
\n\u2022\u00a0Exhaust stroke — The piston moves back to the top, pushing out the exhaust created from the combustion out of the exhaust valve.
\nRemember that the diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine. In the next section, we’ll examine the diesel injection process.<\/p>","protected":false},"excerpt":{"rendered":"
The difference between a gasoline and a diesel engine \u00ac”What is the difference between a\u00a0gasoline\u00a0and a\u00a0diesel engine?” Diesel’s story actually begins with the invention of the\u00a0gasoline engine. Nikolaus August Otto had invented and patented the\u00a0gasoline engine\u00a0by 1876. This invention used the four-stroke combustion principle, also known as the “Otto Cycle,” and it’s the basic premise […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2413","post","type-post","status-publish","format-standard","hentry","category-news"],"acf":[],"yoast_head":"\n