If you can afford to, all cars should ideally be replaced at 2 to 3 years or 50,000 kms.
The amount of money spend on replacing parts it's better to upgrade every 2 to 3 years.
Rest if fuel average is your only concern Yaris might be good. But is a down grade from a Corolla.
Add some money from 1.5 Yaris and go for 1.6 L Corolla Altis
You might miss on keyless smart Entry, Push Start and Climate control AC. But eventually a better car