Another update,
The grade of oil for an engine is important, and the grade recommended by the manufacturer for the operating conditions is even more important, at least as far as warranty is concerned. The oil grade is even more crucial when it is acting as the engine coolant (air cooled engines).
Here is Husqvarna's recommend in their revised (2018) owners manual on PDF, from their site specifically for the GT48DXLS (only engine on the DXLS was a Kawasaki FR730V, and the only mower deck was a fabricated).
The only grade of oil they show for their Dealer only toughest GT is SAE 30 or SAE 5W30, API SJ-SN, oil capacity 2L. I'm sure the motor will be fine with this grade except that The manufacturer recommends up to SAE 40 for hot temp and has no recommendation for SAE5W30. The API is SF, SG, SH, SJ, or SL, Where is SN? Right not recommended for the Kawasaki FR730V motor, but Husqvarna can't seem to read the data from Kawasaki's publish data. The oil capacity without filter change is 1.8L and with filter change, 2.1L. This is Kawasaki's owner's manual for the FR651V, FR691V, and FR730V in PDF from Kawasaki's web page below,
The battery size recommended from Kawasaki in the same manual,
Again Husqvarna,
Maybe the difference is not noticed much, but when it comes to longevity of the motors stator and Husqvarna as a company giving you their best (the line they sell their customers), or at least giving you the customer the correct information for maintenance, this is just one more discrepancy. When adding up all the misinformation together......... well.....again.....
Beware of Husqvarna Garden Tractors!
As a note, they still won't talk to me, after I did the work to prove them wrong in their denial answers, to include their Tuff Torq deception I talked with Tuff Torq about the capabilities of the K66 (mis-representing Tuff Torq in a legal answer, denial of warranty).