Echoing what others have already said..
With hybrid your driving style would be a key thing, am able to get 50-53 on combined motorway on A road, by sticking to the legal speed limits
Is300h has a bigger engine and anything around/above 50 mpg is really good, alternate choice could be CT200h, again with driving you should be able to get late 50s or up to 60 in terms of mpg..
All the best