once you change your oil and filter on time, its unlikely you'll ever get any oil related issues with any modern mineral or synthetic oil.
from every thread on 2nr of this nature, it just seems to be personal preference as there is never any concrete reason to choose one over the other.
As said above, mobile is good and $65ish a quart.
I have used QS mineral, Mobile and RP and honestly i have to say i noticed little if any difference. i just continue to use RP cuz the powerseller delivers it to me and its frickin PURPLE...
