I recently noticed that our Tucson described above has a very noticeable rough range right at about 1800rpm, then goes away after 2000rpm regardless in park or neutral, AC on or off, ECO on or off, and when accelerating slowly through the gears. It will not do this when you get on the pedal from a stop. I cannot find anything specifically on this topic, but I have read of other makes/models doing this, and the fix is either...
(1) Clean MAF, (2) Look for air intake leaks between MAF and TB, then (3) Crankshaft Position Sensor.

Any similar problems out there?