Sensitivity 86 v 90

I am considering an upgrade from speakers with a sensitivity rating of 90 db, 4 ohms, to larger speakers rated at 86db, 8 ohms nominal.  Same brand, PMC. My tube integrated amp is 80-112 watts triode/ultralinear, and it’s fine for my 90 db speakers.  Although, it is sometimes at around 4 o’clock on the volume control, approaching the max at 6.  I am aware of the “amp power must double for each 3db increase in volume” rule of thumb, but really have no practical experience with this.  I do like having 90 db efficiency, always assumed that meant a less powerful amp would suffice. 

   My question is, would the decreased efficiency be a concern?