I thought this was interesting. Mercedes recommends many, many different viscosities for the GLC.
VISCOSITIES:
All TEMPS....0W-30, 0W-40
Above -13 F .5W-30, 5W-40, 5W-50
Above -4 F .10W-30, 10W-40, 10W-50, 10W-60
Above 5 F .15W-30, 15W-40, 15W-50
Above 23 F .20W-40, 20W-50
In contrast, Nissan only recommends 0W-20 in my '21 Titan.
VISCOSITIES:
All TEMPS....0W-30, 0W-40
Above -13 F .5W-30, 5W-40, 5W-50
Above -4 F .10W-30, 10W-40, 10W-50, 10W-60
Above 5 F .15W-30, 15W-40, 15W-50
Above 23 F .20W-40, 20W-50
In contrast, Nissan only recommends 0W-20 in my '21 Titan.