All this oil talk is confusing to me. I want to find the best synthetic to use in my 2003 VW Rialta/Eurovan with 148K miles on it. I'm leaning towards 5w30 or 5w40 as those are the two VW recommended, but several folks say they use 10w40. Which brand of synthetic should I be considering for my VW engine? Thanks! I tried to search the form several times, but the dates searched thing was a mystery to me and I never got any results. If someone could explain how to use the search dates, I'd appreciate it.