(18 May 2016, 6:42 pm)BusLoverMum wrote Typically, the Max routes are the X services, either involving a long non-stop stretch eg the A66 or places where they're limited stop. Some of the Sapphire services are very long - the 22 and 24 are both a 3 hour round trip Durham - Sunderland/Hartlepool - Durham (the drivers must need a bladder like a hot water bottle!) There are some exceptions, though - the X21/X22 Ashington-Newcastle services are Sapphire, for example.
I think it was said that the 46 would be renumbered X46 in line with the MAX upgrade. Nothing was ever mentioned of the 48 being marketed as a MAX service, though, despite services 46 and 48 still interworking once the MAX upgrade is done.