After the "Eye of Universe", every ship's sensor range gets set to 15, including ships I specifically design to have more sensor range (with enough miniturization, you can fit about 15 or so sensors on your huge hull making the range about 33 or thereabouts.)
This is really a pain on the huge 16x16 galaxies. My ships have a speed of 50 but can only see 15 spaces in front of them.