Xw40 is pretty much only a Euro formula viscosity, I don't think they've ever offered any specialty versions of Euro Oils since to meet their baseline specs they're essentially and Extended Performance oil, then trying to break it out into High Mileage or other varieties would be attempting to split and already small market niche into even smaller categories, and 10W40 has been declining in popularity for years Mobil 1 only offers it in HM variety and it probably sells in lower volumes than even the Euro oils at this point.