To improve the fuel efficiency of your Daihatsu Mira 2014:
Check the air filter: A clogged or dirty air filter can restrict airflow to the engine, negatively impacting fuel efficiency.
Optimize driving habits: Adjusting your driving habits can significantly affect fuel consumption. Practice smooth acceleration and deceleration, avoid excessive idling, and maintain a consistent speed whenever possible. Additionally, minimize the use of heavy accessories or unnecessary electrical loads.
Tire pressure maintenance: Ensure that your tires are properly inflated according to the manufacturer's recommended pressure. Underinflated tires can increase rolling resistance, leading to decreased fuel efficiency.
Fuel quality and brand: While you mentioned the type of engine oil you use, it's also essential to ensure that you are using good quality fuel from reputable stations. Poor quality fuel can affect engine performance and fuel economy.
I hope it helps
Regards
Nabeel