I believe you posted this in the Bobcat forum, but I happen to have quite a bit of experience with NH's and SSL's in general, so I thought I'd respond. Of course your operator's manual is the most for sure place to get this info, but we all know they don't always give you too many options. There are so many oils out there and different variables that it is easy to be conservative in recommendations in this area. In general if you use a clean, good quality (doesn't have to be the most expensive), petroleum based oil in this machine you are most of the way there. I don't think this machine was ready for bio oils, but even they would work fairly well and only shorten the life of components (how much depends on many variables). ISO 32 is a bit lower viscosity (thinner) than most hydraulic systems like your SSL would like to see ideally, but given that you are not operating in excessively hot ambient temperatures this should not be a big deal and will actually be better for those -15°F days. One way to make sure is to watch the hyd temp (easy to do on the NH's as I remember) while working the machine hard for an extended period WITHOUT STOPPING (~ 1 hour will typically do it). Doing this on a hot day will give you the best confidence. Ideally the temp will rise for a while and then level off no matter how long you continue to run it. If it keeps rising seemingly for ever, you could have an issue. I doubt this will be the case. You will probably level off in the 170-180°F range. Of course there is a warning system that will warn you if you get over a certain temp (not sure what this is se at on NH's) and if you get this then you definitely have an issue. Again, probably not the case. I imagine you are safe in your situation especially if you're not running the machine too hard (like most operators). I would tend to recommend ISO 46 or SAE 10W-30 (engine oil) in most cases to be even safer. I wouldn't go draining out your new oil though. Hope this helps.