Diesel buses are large vehicles powered by diesel engines, which use diesel fuel to operate. They are commonly used for public transportation in cities and towns, providing a reliable way for people to travel. Diesel engines are known for their fuel efficiency and ability to carry heavy loads, making them suitable for transporting many passengers at once. These buses typically have a longer range than electric buses, allowing them to cover greater distances without needing to refuel frequently. However, they produce emissions that can contribute to air pollution, leading some cities to explore cleaner alternatives for public transit.