I've been noticing in recent VOA's of Mobil 1 Euro, Leichlauf, etc. that the 0w40/5w40 oils have been on what seems like the thinner side, almost closer to a 30w. We know that VW 502.00 covers multiple 30w and 40w oils, however my tuner suggests a 40w with the tune and turbo setup on 2 of my VW's for what he calls "extra security" with a little thicker oil. Im wondering which oil covers this spec that hasn't been reformulated to be on the thinner side, do we know? Does it really, really matter? Would a 50w oil be a better choice? 2015 GTI and 2015 Jetta for reference. Much appreciated