When driving a commercial passenger bus in high-altitude plateau regions (such as Qinghai-Tibet plateau highways), what physical vehicle changes must the driver anticipate?

1. Atmospheric pressure drops, reducing engine oxygen intake (causing engine power drop) and lowering the boiling point of coolant; brake heating increases during descents
2. Atmospheric pressure increases, causing the engine to gain 50% more horsepower
3. Tire pressure automatically drops to zero due to thin air
4. Plateau air eliminates the risk of brake fade entirely