The coordinates in the grid in QGis composer display incorrectly when using the "degrees, minutes, seconds" option (or even decimal degrees). It displays West and East in the longitude and North and South in the latitude (or positive and negative) and sometimes it even mixes UTM and degrees.
It doesn't seem to have any problem with decimal format (UTM) as shown below, but no matter what I do it still has the same trouble with degrees.
I have done multiple maps in QGis 2.14 and 2.12 having the same problem and I remember that in earlier versions this did not happen. Is there any way to fix this?
June, 2018: It seems new versions of QGis don't have this problem.
Best Answer
I've just found out what's going on. You have to switch interval units from "millimeters" or "centimeters" to "units of map". Then the software will use the shp coordinate system to generate the grid.