Hello, Ken. Given the freezing point of petrol is a chilly -60°C or -140°F, it’s virtually impossible for a petrol tank to freeze up during even the harshest winter. Diesel on the other hand has a much higher freeze point, and is prone to gelling in cold weather conditions. However, what actually causes freeze ups in engines is the condensation that naturally accumulates –most commonly known as having water in the tank. This accumulated water has a tendency to drop to the bottom, and, when if freezes, does not allow the fuel to flow properly –or not at all. Anti-freeze additives or “dry-gas” additives, such as HEET are designed to reach the ice, defreeze it and then break it into small, easily combustible particles, and that’s how the water is expelled from the system.