My Kanga calls for AWS 68 Hydraulic fluid, which is expensive and hard to find. I was curious what the other mfg's specs call for in terms of hydraulic fluid. Viscosity breakdown is presumably the reason for the thicker fluid spec, but the only attachment i use which would heat up the oil is the tree auger which is used intermittently. What do you guys think? Will the lighter weight, 46 fluid be OK?