If you want to the most useful life out of that engine, put an oil catch can on it, and don't worry about the dealer's non-sense. Turbos create more blowby that NA engines.
Look on the bright side. My mother once became convinced she was overdue for several major services, like say 30K, 50K, 60K etc. She went in to the dealer and demanded they do ALL of them! Fortunately they were honest enough to tell her there was a lot of redundancy in those services..... They only need to change her oil one time, not three, etc.
I understand your viewpoint but I feel that regular intake valve cleanings on DI vehicles is a worthwhile procedure because its easier to keep them clean vs waiting until its too late then you have to do the costly walnut blast cleaning to clean them. I don't believe in paying someone $100+ to do it though - a can ran thru before each oil change yourself for $10-15 is sufficient and preferred.
Should be in specification fluids and capacity section of your owner's manual. Amsoil site says GL5 75W90 for transfer case - should be same for light duty 3rd member. I have had good luck with semi syn or syn Valvoline gear oils in the juice bags.
