I have 1520 hydrostat (since '95). I have always changed the hydro/hydraulic oil & filters every 300 hours. Last time I stopped for oil at a NH dealer, they did not have Multi G-134 and said to use Mastertran (both NH-Ambra oil). By looking at the specs, I cannot find where it says that Mastertran can be interchanged with Multi G-134. Any knowledge or experience with Mastertran in NH compacts?