Which is todays best 150cc bike for mileage ?

Depends on your budget. The best compromise among good mileage, good reliability and comfortable rike (sic) is HH Hunk. Most VFM bike in this category is the Apache RTR 160 (carb), though.

Hi, the new Honda Unicorn is the best bike in the 150cc bike segment. It has a reliable 150cc, 4-stroke, Air-Cooled, OHC, Single Cylinder engine with a power of 13.3 bhp @ 8000rpm and torque of 12.8 Nm @ 5500rpm and has 5 Speed gear box. The new Honda Unicorn has an overall mileage of around 52-58 kmpl depending upon the riding conditions and style. The Honda Unicorn with reliable engine and quality body parts, good mileage, decent power, very good comfort in riding and handling makes it the best all rounder bike with true value for money bike. Another option for decent mileage and stylish sporty looks is the Yamaha SZ-R with 150cc engine and with power of 12.1 hp @ 7500 rpm which is less compared to new Honda Unicorn and having mileage of around 50 to 58 kmpl. so better test ride both the bikes and take a wise decision.