We compared the features of the Yamaha MT-15 Vs MT-03 & here are the results…

MT-15: 155cc liquid-cooled single-cylinder engine -- MT-03: 321cc liquid-cooled twin-cylinder engine

Smaller MT gets VVA (Variable Valve Activation); MT-03 doesn’t

Both feature LCD instrument consoles…

… but the MT-15 gets Bluetooth connectivity, while the bigger MT doesn’t!

MT-15 also gets traction control, which the MT-03 misses out on

Both the MTs are equipped with an LED projector headlight & all-LED lighting

The smaller MT has a side stand sensor, which the MT-03 loses out on

Both have inverted forks -- MT-15: Linked-type monoshock -- MT-03: Preload adjustable monoshock

MT-15: 282mm front disc -- MT-03: 298mm front disc -- Both get 220mm rear disc, with dual-channel ABS

Smaller MT-15 at Rs 1.67 lakh packs more features than almost 3x costly MT-03 at Rs 4.59 lakh (both prices ex-showroom)