In an earlier project, I used an LED to indicate power (this 12V model). The PSU delivered +15V. I adjusted brightness with a 5k series resistor. According to the datasheet, this particular white LED has a forward voltage of 3.8V. According to the same datasheet, I slightly exceeded the max operating voltage, but it seems to have caused no problems so far.
I now want to use the same model LED (I have several left) on a different project which has a +20V PSU, and I want to match the brightness of the LEDs on the two projects. While exceeding the 12V LED's rating by using a 15V PSU might have worked, 20V seems like it's too much. I thought I'd try a voltage divider here, as follows (iCircuit screenshot, old circuit on the right, new circuit on the left):
According to the simulation, the LED receives the same current and voltage in both cases, and the resistors dissipate pretty small amounts of power, so should not overheat. Is this a reasonable approach?