Used car purchase in 2025

I’m on a tight budget of 03-04 lakh

1. Which engine option should I choose petrol or diesel?
2. Consider the ethanol blend case with petrol. Could we anticipate isobutane blending with diesel in any near future?
3. I’m preferring to Portuguese Skoda or Volkswagen diesel vehicles which are around 10 years old. Is this right option to do?