Gear lubricant equivalents to Mobil SHC 634 include BP Enersyn HTX 460 and Castrol Alphasyn T 320. Additional Mobil SHC equivalents include Elf Epona SA 320 and Shell Delima HT 320.
BP uses poly-alpha-olefin fluids and sulphur/phosphorus anti-wear technology to produce the Enersyn HTX 460 gear oil. This production process gives the oil thermal stability and greater load-carrying capacity. HTX 460 has a density value of 870 and a viscosity index value of 160.
Castrol Alphasyn synthetic gear oils use stable poly-glycol base fluids and complex additives to improve load-carrying capacity, thermal stability and oxidation. Elf Epona SA 320 has a density value of 860 and a viscosity index value of 150.