Royal Enfield Thunderbird is having less mileage compared to other series of Royal Enfield, I have tested the bike with one litre of petrol in both city and highways with other series. And in long ride I have to change the clutch cable for three times in 1500 km, Suspension of vehicle is not so good, pilon seat rider gets body ache after 50 km. Oil changing is a big issue in Royal Enfield Thunderbird edition