Which Bajaj Avenger bike is better for city riding?
All the three models of Bajaj Avenger bikes (Street 150, Street 220 and Cruise 220) have same length, width, height, ground-clearance and wheelbase even tyres, suspension and fuel tank capacity is also same and there is not much difference in weight; as per users experience Avenger Street 150 is better for city riding for it delivers better mileage.
You also asked about the cooling types:
Air Cooled System
In air cooled system the engine cylinder is surrounded by fins on the outside. These fins facilitate the cooling by increasing the surface area which is exposed to air for cooling. Air cooled engines are easier to manufacture and also pretty easy to maintain are pretty optimal for low capacity bikes where price is a concern as well as where high performance is not an important requirement.
Oil Cooled System
In oil cooled system oil is circulated between the radiator and the engine case, the radiator takes off the heat from the oil, thus bringing down the temperature. Oil cooling is just air cooling with an additional cooling mechanism.
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