Most probably no gain at all using M1 ESP X4 0W-40 (Porsche C40 & VW 511 00 like M1 ESP X3) over running common VW 504 00/C30 just like M1 ESP 5W-30 for the vast majority of engines. Marginally higher viscosity at 100°C, marginally higher HTHS (when Virgin-like only!), but at the same time also...