I mine øre voldsomt interessant emne... ligesom "variable compression ratio", mener Saab var tidligt på banen her....
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http://fpn.dk/motor/article1022016.ece
Mercedes-Benz DiesOtto – a further development of the spark-ignition engine
" In line with the worldwide success of today's diesel engine, vehicles equipped with gasoline engines will continue to have a long-term attraction for many customers and in many markets. Accordingly we are giving our attention to both engine types – including a full hybrid option for diesel and gasoline vehicles, " says Prof. Kohler. Mercedes-Benz is working on its DiesOtto concept with corresponding emphasis. Its key technological features are as follows:
- Downsizing with fewer cylinders and a smaller displacement
- Turbocharging for superior performance
- Direct gasoline injection as a further fuel economy measure
- Controlled auto ignition, a combustion process similar to that of a diesel
- Variable valve control
- A variable compression ratio leading to even better fuel economy and, depending on customer needs and the type of operation,
- A hybrid module with an integrated starter/generator, which makes the drive unit even more economical.
When starting and under full load, the fuel/air mixture is ignited by a spark plug, as in a conventional spark-ignition engine (homogeneous combustion). The controlled auto ignition to which the DiesOtto automatically reverts within its working cycle occurs under partial load conditions, i.e. at low and medium engine speeds.
The result is the very low nitrogen oxide emissions of homogeneous combustion at reduced reaction temperatures. All further emissions control in the DiesOtto engine is by means of a standard three-way catalytic converter. A highly efficient engine management and control system has also been realised to combine the individual sub-systems into a drive concept.
The current prospects for the future of the internal combustion engine reveal its great potential, and show that the new drive concept is a feasible proposition in the mid-term. Some of the intermediate solutions incorporated, e.g. direct gasoline injection, are already in series production at Mercedes-Benz. Others will be gradually integrated into series-production engines until the overall solution has been realised.
i forhold til "almindelig" dirrekte indsprøjtning eller op i mod 35% i forhold til en almindelig bil i dag, desuden kom man ud over de ulemper man havde med dirrekte indsprøjtning i forbindelse med "lean burn" (de forhøje ??? Nox ??? kan ikke huske hvilken værdier, der er for mange af når forbrændingen er for kold)
til de langhåret