The report below shows the first 2 UOAs on the G37 I bought last fall. The results from March were with Quaker State Full Syn 5-30. It was the first time I've ever had a QS test with that low of a viscosity number, but I've read that this particular engine is rough on oil. The next test was done with PPP for the same amount of miles. As you can see the viscosity isn't much better, although the TBN was certainly stronger. The PPP also has almost half the Moly of the QS. It can be debated whether that is significant.