Gasoline

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Why do we use gasoline for small vehicles and diesel fuel for big vehicles? – Methdini, age 15, Sri Lanka Gasoline fuels most light-duty vehicles, such as passenger cars and pickup trucks. Heavy-duty vehicles, like buses, delivery trucks and long-haul tractor-trailers, typically run on diesel. Both fuel types are needed because gasoline and diesel engines have different strengths. As my automotive engineering students learn, this makes them suitable for different uses. Let’s start with what they have in common. Gas and diesel engines both work through a process called internal combustion. First, they mix fuel with air because the fuel needs oxygen from the air to burn. Next, they compress the fuel-air mixture, which ma...

Fossil fuels are the leading driver of climate change, yet they are still heavily subsidized by governments around the world. Although many countries have explicitly promised to reduce fossil fuel subsidies to combat climate change, this has proven difficult to accomplish. As a result, fossil fuels remain relatively inexpensive, and their use and greenhouse gas emissions continue to grow. I work in environmental and energy law and have studied the fossil fuel sector for years. Here’s how fossil fuel subsidies work and why they’re so stubborn. What is a subsidy? A subsidy is a financial benefit given by a government to an entity or industry. Some subsidies are relatively obvious, such as publicly funded crop insurance or research grants to help pharmaceutical companies develop new drugs. Others are less visible. A tariff on an imported product, for example, can subsidize domestic manufacturers of that product. More controversially, some would argue that when a gov...