i fought these days with 2 3 guys , wich were level 30 to 31, and i was level 27...so the matchmaking is with 4 + - at the 27 lvl range
Are you sure that you were matched up against lvl31 mech while you were using lvl27 mech? Perhaps you installed lvl28 kit (or some other item) to your mech without realizing it?
For example, my lvl28 mech's matchmaking range is 25-31. I can't battle with lvl24 or lvl32 mechs.
Same goes when i use my lvl20 mech, my range is 17-23, i can't battle with lvl16 or lvl24 mechs.
I also asked admin about this change and she said it was in discussion between the devs few months ago. It seems they indeed implemented it into the game.
Next time, when searching for an opponent, pay attention for how far the matchmaking range stretches. E.g. first it's 27, then 26-28, then 25-29 and then 24-30.