I think it's one of the most popular things in action films: Cars exploding.
In reality, a car explodes very rarely, even when it gets shot. However, what fuel type tends to explode more?
Diesel is similar to kerosene. It has a relatively high ignition temperature. So, it's very unlikely that diesel will be ignited by bullets.
Kerosene is vaporizing at a specific temperature. Below this temperature, kerosene is perfectly secure, but when exceeding it, the vapor is a highly-explosive mixture. And this mixture can be ignited easily.
I don't know if it's the same with diesel, but as it is similar to kerosene, it could be.
Petrol can be ignited easily. Maybe even by a bullet. There is also a petrol-vapor, that is explosive as well.
So, what type of fuel would make most sense if we see a car exploding in an action film?