[Shop-talk] Hydraulic fluid question

[Randall]

>  Does that viscosity number factor like regular
> oil? In other words, higher number, thinner oil?

Er, no, in both cases a higher number means a thicker oil (at a constant
temperature).  

But "10 weight" covers a range of centistokes values, and apparently 46 (at
40C) is within range, so the oil you have should be fine.  Pour point of ISO
46 is under -20F, so you should be fine @ 40F.

Randall