I would like to clarify few points here:
1. The query raised was for cars available in India and I don't thing Gasoline direct injection cars are commonly available in India. If the Gasoline DI cars are made available, the cost difference won't be much. But still the fuel injection system manufactering cost for diesels would be higher.
2. 200 bar injection pressures for diesels was long time back in 20s and 30s. Therefore, the gasoline engine makers do not have to carry out heavy research on building new technology for fuel equipments. They carry research on modifying the system. On the contrary, diesel engine maker are still struggling for finding not only the cheaper materials to withstand such pressures, but also the processes to reliably make such equipments. Hence gasoline fuel system cost will be less.
3. The fuel injection control (timing) is more delicate in diesels as there is no spark plugs. But the these system, although a bit complex doese not add so much to the manufactering costs.
4. The thermal efficiency of diesel engines are much higher than gasoline engines. (highest eff achieved has been around 55% for commercial engines)
5. (OT) HP water jet (about 4000 bar) is being used to cut steel and other materials in manufactering processes (special cases) although it is not common due to high cost involved.
6. Regarding governor, please elaborate.
The cars already have ECU for precise fuel management system and I don't think the cost of software can make so much difference in petrol and diesel cars cost (somebody with specialising in this branch, please help). Governors are required where seperate precise speed control is required and where speed is affected by many external factors (e.g. generators, petroleum pipeline pumps etc). In fact, fitting a gorvernor on a car engine can make it sluggish (it doesn't matter if it is a petrol or diesel) |