Max rx input voltage on FT232rl
No. It's not automagic.

You need to specify the "IO" voltage on the VCCIO pin. If you want to use 5V logic then you need to provide 5V to that pin. If you want to use 3.3V logic you must provide 3.3V to that pin.

That pin is basically the power to one side of the internal logic translator circuit.


  +1.8V to +5.25V supply to the UART Interface and CBUS group pins (1...3, 5, 6,
  9...14, 22, 23). In USB bus powered designs connect this pin to 3V3OUT pin to
  drive out at +3.3V levels, or connect to VCC to drive out at 5V CMOS level. This
  pin can also be supplied with an external +1.8V to +2.8V supply in order to drive
  outputs at lower levels. It should be noted that in this case this supply should
  originate from the same source as the supply to VCC. This means that in bus
  powered designs a regulator which is supplied by the +5V on the USB bus should
  be used.


If you set it to 3.3V then try and provide 5V logic signals to it you risk breaking the chip.