M1 5W-30 ESP meets mostly European specifications and has a relatively high HTHS viscosity around 3.5 cP. Unlike most Mobil 1 oils, it has some ester base oil in it. There is an older and newer version and both are still being sold. The newer one has 0.8% sulfated ash (more metallic additives) than the older one which has 0.6% sulfated ash. Both meet same or nearly the same specifications.