when im nice to it i get 10.8 city and about mid 13s highway doing about 75mph and being a little agressive with passing. When i get on it a lot my city falls to 9.8 and highway will be low 11s but im to the floor often when im driving like that. Ive seen as high as high 16s on a long flat road with the cruise control set at 55-60mph. This is according to the overhead counsole though and it tends to be off on some trucks.