For exceeding the speed limit by 51-60 mph on a motorway, the maximum penalty is a fine of up to £1000, a 6-month driving ban and 6 penalty points.
It's important to note that the actual penalty imposed may be less severe, depending on the individual circumstances of the case. For example, if the driver has no previous convictions and the speed limit was only slightly exceeded, the fine may be reduced or the driving ban may be suspended.
It is always best to obey the speed limit and drive safely to avoid any potential penalties or accidents.