For a **gasoline engine**, it is advisable to **start driving immediately after starting the engine**. This is due to several reasons related to efficiency and pollution reduction:

- **Fuel saving**: By starting and driving immediately, unnecessary fuel consumption that occurs when the engine is idling (running without the driver pressing the accelerator) is avoided. Prolonged idling can increase fuel consumption.

- **Pollution reduction**: Engines that remain idling emit more toxic gases into the atmosphere. By starting to drive immediately, the emission of these gases is minimized, contributing to a cleaner environment.

- **Catalyst protection**: The catalyst, a device in the exhaust pipe, helps reduce pollution. Starting and driving immediately allows the catalyst to function more efficiently, as it heats up faster and begins to reduce toxic gas emissions.

For these reasons, it is more efficient and environmentally friendly to start driving right after starting the engine.