Reader Thompson Ng wrote in to askST: "How do you prevent your car engine from overheating and catching fire on a hot day?"

Senior transport correspondent Christopher Tan answers.

Cars are made to manage a whole range of weather conditions. Many imported by authorised agents are "tropicalised" to cope better with the hot and humid conditions here.

Hence they are unlikely to overheat, even if some of the older European (non-German) models have been known to do just that.

By "older", we mean those from the early 1990s or earlier.

Car fires are rarely caused by an overheated engine. If an engine overheats, the car will just stall and you will see "smoke" rising from under the bonnet. That is not from a fire - it is the steam from the radiator.

Most vehicular fires are caused by electrical short circuits. Failed insulation, bad wiring or a high electrical load (sometimes from modifications or the installation of an aftermarket component) can contribute to this outcome. That is why some warranties are void if the owner has done such modifications.

Inferior design from the manufacturer can also lead to this. There have been recalls to fix such flaws.

Another cause would be collisions. Sometimes, a serious collision can lead to fuel leaks.

Leaked fuel can ignite, especially in an engine compartment that has been compromised, with its mix of heat and electricity.

So the best way to prevent your car from catching fire is to ensure it is not tinkered with. If you do not want it to overheat, ensure it is well maintained and the radiator is suitably filled, and drive safely to minimise the risk of collisions.

Reader Thompson Ng wrote in to askST: "How do you prevent your car engine from overheating and catching fire on a hot day?"

Senior transport correspondent Christopher Tan answers.