The BMW 5 Series comes with three powertrains: 252PS/350Nm 2-litre petrol (530i), 190PS/400Nm 2-litre diesel (520d), and 265PS/620Nm 3-litre diesel (530d). All three engines come mated with an 8-speed automatic transmission and drive the rear wheels.
Selecting between the variants would depend on the features and fuel type required. 530i am Sport is powered by a 1998 cc petrol engine which is available with a Automatic transmission. Whereas 530d am Sport is powered by a 2993 cc diesel engine which is available with a Automatic transmission. Follow the link for the detailed comparsion of both the variants.
For the exact maintenance and service cost, we would suggest you get in touch with the nearest authorized service center as they would be able to assist you better with the details. You may click on the given link for the service centers in Hyderabad.