Since I put it in just yesterday I can't tell you anything other than for a 7.3 cSt oil that I had reservations about using in this 14 year old motor because it is so light I have great oil pressure .
I would just about be certain that it will get better fuel mieage over the 10 cSt Mobil oil but doubt it's got anything over the 8.8 cSt Synergyn .... nothing hardly does cepting it's 3/30 LTS big brother when one needs a heavier oil