Breakthrough Engine
Date: Aug 3rd, 2007 6:49:26 am - Subscribe
Mood: secretive
Just when almost all of us are thinking that gasoline engines are out and diesel is in, Mercedes-Benz came up with an engine that would make us think twice about the future of gasoline engines. It has been described that the developments made on diesel engines today can be compared to the advancements made to the gas engine in the 80s and 90s.
This is true, of course. After all, a diesel racecar has won the prestigious 24 Hours of Le Mans two years in a row. But it does not necessarily mean that advancement of gasoline engines has stalled.
One concrete, or should I say metallic, reason is the DiesOtto from Mercedes-Benz. Must be named after Rudolf Diesel and Nicolaus Otto with the former being the inventor of the diesel engine and the latter the one who conceptualized the four-stroke engine. Actually, the name is derived from a combination of German words for diesel and gasoline. But why the reference to diesel engines, you ask? It’s because the engine in question has the capability of a diesel engine.
One of the major differences between gasoline and diesel engines is the presence of a spark plug. Gasoline engines use the spark plug to ignite the air and fuel mixture inside the combustion engine. Diesel engines, on the other hand, use the heat of compression to ignite fuel. Because of this capability of a diesel engine, it is deemed to be more powerful than gasoline engines although not as clean.
The DiesOtto has a spark plug. Then it’s a gasoline engine, right? Of course it is. Those spark plugs though are only used on certain operating conditions. The engine ignites the fuel with the spark plugs when starting the vehicle or at high speeds. But when it is cruising at a slow speed, it does not use the spark plugs. That’s what’s amazing with this engine.
According to the makers of this engine, they used what they call the Homogenous Charge Compression Ignition or the HCCI. Basically that means that in the compression stroke at low and medium speeds, the heat produced by the compressed air inside the combustion chamber is enough to ignite the gasoline fuel that will be injected into the combustion chamber.
The DiesOtto is really impressive. The prototype made by Mercedes-Benz is a 1.8-liter four-cylinder engine but it produces 238 horsepower. In current conversion, that power would be comparable to the output of a standard 3.5-liter V6 gasoline engine or a 3.0-liter V6 diesel. Fuel efficiency is also noteworthy. According to results of the tests conducted on the engine, it will consume a gallon of gasoline for every 40 miles traveled.
When will it be mass produced? Prof. Dr. Herbert Kohler of Mercedes-Benz’ advanced engineering arm says: “In the mid-term we will have something like this in production.” In plain English, wait for five more years. But it will be worth the wait.