Originally Posted by critical

Viscosity is just the fluid's resistance to flow. You don't need to get it to a certain point, unless you're talking under extreme conditions but we're not. The power steering works perfectly fine at ambient temps as it is a very viscous fluid-Redline D6 ATF has a viscosity index of 166 (110 is very high). I'm going to go on a limb and say there's no way you can overcool it.