In my experiment to run QSUD 5W20 I have already added 1 qrt. of make up oil by the 3,100 mile mark on my way to a 3,750 mile severe service OCI . I wouldn't even consider my driving anything other than average suburban driving with my daily work commute being 40 ~ 45 minutes one way . Both the older PFI engines in my signature don't burn a drop of oil during a OCI - not the case with the newer GDI Sonata , so what gives with GDI engines using / burning oil when broken in by the book and factory fill changed at 1K miles with synthetic oil used it's whole life to date ?