I've got the 5/20 SR-1 in my Miata now after a 1200 mile run on the 5/30 SR-1 .
No noticable loss in oil pressure over Mobil 5/30 Supersyn or Synergyn 0/20 run in the past at hot idle .
Me likey's it !
I sent the 5/30 to the lab yesterday via US Priority because the last 3 samples I sent were stinkin lost and one was a virgin Torco 5/20 .
Just about no sense in buying the prepaid mailers anylonger since 9-11 , for me anyway .
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
Thats my Synergyn plug for the day