What is the main idea of the passage regarding future cars?

The passage is likely centered around the notion that while there are discussions surrounding the development of new fuel types, this project needs to be approached with caution and perhaps should not be rushed. The assertion to delay new fuel development implies that thorough considerations—such as research, testing, and sustainability—are necessary before widespread implementation. This reflects a balanced attitude toward technological innovation in the automotive industry, emphasizing the importance of ensuring that any new fuel types are safe and effective before they are introduced to consumers.

The main idea hinges on the principles of careful planning and assessment in technological progress, especially concerning environmental impact and practicality. Understanding the complexities of fuel development, including factors like efficiency, cost, and environmental protection, leads to a more prudent approach, hence the reasoning for delaying rather than rushing into it.