The engine displacement of Bajaj Discover 125 (2007-2015) is 124.6cc. It is equipped with a 4-stroke, single-cylinder, air-cooled engine, with a maximum power output of 11.8 PS at 8,000 rpm and a maximum torque output of 10.8 Nm at 6,000 rpm. This engine provides a good balance of power and torque, making it ideal for everyday use.

Bajaj Discover 150F is the most powerful motorcycle out of all the option in the query. It is powered by a 144.8 cc, 1-cylinder engine producing 14.3 BHP and 12.75 Nm of torque. It comes mated to a 5-speed gearbox and weighs just 132 kg. This makes it the most powerful motorcycle among all the above. It comes with a price tag of INR 58,000 for the disc brake variant and INR 62,000 for the drum brake variant. Another good option would have been the Bajaj Pulsar 135 LS, retailing for a price tag of INR 58,002.

Bajaj Discover 150F is a better bike when compared to the Discover 125. The former comes with a bigger 144.8 cc engine producing 14.5 PS and 12.75 Nm of torque. The values are very nice for a bike starting with a price tag of INR 58,000. The motorcycle carries a semi-faired design which enhances its overall looks while the design used by Discover 125 is nearly decade old. It just benefits on the mileage part but that too is minimal if both are riding on highway speeds. Discover 125 looks modern and even uses a semi digital instrument console.