Race cars generally do not use diesel engines, as they are more commonly powered by gasoline engines due to the performance benefits they provide. While diesel engines are known for their efficiency and durability, gasoline engines are typically preferred in racing due to their higher power output and faster acceleration.

There are several reasons why race cars use gasoline engines instead of diesel engines. One of the main reasons is the weight and size of diesel engines. Diesel engines are typically heavier and larger than gasoline engines, which can impact the overall weight distribution and handling of a race car. Gasoline engines are also known for their higher revving capabilities, which allows for faster acceleration and greater top-end speed.

In addition, gasoline has a higher energy density compared to diesel fuel, which means that gasoline engines can produce more power in a smaller, lighter package. This is important in racing where every ounce of weight and every ounce of power counts towards achieving maximum performance on the track.

Another factor to consider is the availability and regulations surrounding fuel in motorsports. Gasoline is the most common type of fuel used in racing events around the world, which means that race teams have easier access to high-performance fuels. Additionally, many racing series have specific regulations regarding the type of fuel that can be used, often requiring teams to use gasoline rather than diesel.

However, there are some exceptions to this rule. In certain endurance racing events, such as the 24 Hours of Le Mans or the World Endurance Championship, there are classes of cars that do use diesel engines. These diesel-powered race cars are known for their fuel efficiency and can often go longer distances on a tank of fuel compared to their gasoline-powered counterparts.

Overall, while diesel engines are known for their efficiency and durability, they are not commonly used in race cars due to their weight, size, and lower power output compared to gasoline engines. Gasoline engines remain the preferred choice for most racing teams due to their performance benefits and availability of high-performance fuels.