When considering hydraulic oil, a question we often receive is “which is better, AW32 or AW46?” The short answer is that neither is better or worse. Ultimately, there are several factors that must be considered to determine which is the better option for your lift and your shop.
An oil’s rating refers to its viscosity, which determines its ability to flow at different temperatures. Lower numbers indicate thinner, more easily flowing oils. As such oil rated as AW-32 is neither better or worse than one rated as AW-46. The numbers refer only to the viscosity – AW means Anti-Wear – not to the quality; oil quality is dependent upon the manufacturer.
For Atlas above ground lifts, AW-32 will flow better in colder weather than AW-46. Customers in colder climates (with unheated garages or service areas) may want to use AW-32. Above ground lifts located in heated garages (or warmer climates) may use either AW-32 or AW-46. If your lift is located in a region that has a colder climate and you intend on using your lift (frequently) when the temperature is below 32 degrees, then you may want to consider automatic transmission fluid rather than hydraulic oil. We do not recommend the use of transmission fluid because its thinner viscosity (5W) can allow the oil to “weep” (around hydraulic cylinder seals) and transmission fluid may also reduce the life expectancy of the pump seals.