When it comes to selecting the best engine oil for hot climates, it's important to look for oils with high viscosity index (VI) and thermal stability. High VI ensures that the oil maintains its lubrication properties even in high temperatures, while thermal stability prevents the oil from breaking down and forming deposits. Synthetic oils are typically the best choice for hot climates, as they have superior high-temperature performance compared to conventional mineral oils.

A good choice for hot climates would be an oil labelled as "full synthetic" with a viscosity grade of 5W-30 or 5W-40. These oils have been specifically formulated to maintain their viscosity in high temperatures and provide reliable protection for the engine, even under extreme conditions. Always consult with your vehicle's manufacturer or a trusted mechanic to determine the best engine oil for your specific make and model.

Original Source: https://www.quora.com/Which-engine-Oil-is-the-best-for-car-engine-especially-in-hot-places/answer/Leicester-Motor