I have an old Vauxhall Corsa that we use as a little runabout. It needs new front pads but I have also checked the discs and one disc is very scored and the other is smooth. Can I get away with just changing the damaged disc and leaving the other one as it is a cost difference of over £50 (I know that ideally you should change them as a pair but I just wondered if I could save a bit of money as it's an old car)
in my opinion, to be on the safe side, change the both, i work at a motor factor and when a single disc gets booked out to a customer, i always think to myself, "that car probably wont brake in a straight line, good luck with that one.", its up to you but you pay to be safe at the end of the day. its a cost difference of one disc or a whole car when it veers into a hedge or worse, oncoming traffic.
many manufacturers refuse to sell a single disc, they will only supply in pairs and that is how they should be fitted for safety reasons...
You need to ask yourself why is only one scored ? seized/sticking caliper ?