(05 Mar 2021, 9:00 pm)GNE6312 wrote Tbh I would have said a volvo is more suited than 7510 for the X30 seeing as a majority of the X30 route is motorway and 7510 having a speed limiter (which realistically should be removed or increased)

They probably are, hence why they are used ahead of 7510 on the X20 when required, but its likely 7510 will be preferred given its age, appearance etc. 

7510 is limited by it's differential if I remember correctly. There is/was a high speed one in the shell of 7513 which should have been put into 7510, however that still hasn't happened for some reason.