I've been running Pennzoil Platinum 0w-20 in mine. I haven't done a UOA yet, but it doesn't sound unhappy. I know some people think they're snake oil, but I installed a UPR oil catch can and was shocked at the amount of oil that gets sucked back into the intake via the PCV system. Even if it doesn't make a difference, I feel better knowing that I kept that oil out if the intake and off the valves, not to mention out of Nissan's sensitive catalytic converters.