How to use SelectedIndexChanged-Event of ComboBox

Question

I have a ComboBox with two read only values: white fusion and silver fusion.
How do I get the correct method to run based on selecting each one in a ComboBox? The methods are just pulling an Integer from a SQL table and put it into a TextBox.

private void cboOilVehicle_SelectedIndexChanged(object sender, EventArgs e)
{
    if (cboVehicle.SelectedIndexChanged == "White Fusion")
    {
        whiteFusionOil();
    }
    else
    {
        silverFusionOil();    
    }
}

Answer 1

private void cboOilVehicle_SelectedIndexChanged(object sender, EventArgs e)
{
  if (cboVehicle.SelectedIndex == 0)
  {
    whiteFusionOil();
  }
  else
  {
    silverFusionOil();    
  }
}

Edit:

The name of the control must be cboOilVehicle (Line 1) or cboVehicle (Line 3), it can't be both. You have to decide which is correct