The GLC has 1991 cc (Petrol top model) engine, while X3 has 1998 cc (Petrol top model) engine. Mercedes-Benz GLC and BMW X3 ex-showroom price starts at Rs 52.75 Lakh for 200 (Petrol) and Rs 60.5 Lakh for X3 xDrive 30i Luxury Line (Petrol). For a detailed comparison, follow the below link - Compare. Moreover, you may have a test drive of the cars for a better idea of comfort and drive quality by visiting the nearest dealer in your city. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Dealers.