few questions servicing

[thad1]

Hey guys,

Front discs and pad's need replacing. I have been trying to figure out if the fronts are 280 or 302mm. www.eurocarparts.com only list the 302mm for the car based on registration number, other places list both sizes lol

Can someone tell me how to work the size out?
I have tried measuring them on the car but it's difficult to get an exact measurement!
Also with regards to pad's I have ruled out standard minetx as they were rubbish on my 9-5 aero, are the black diamond predator pad's any good, been offered fast road ones for just under £50!
Also with regards to oil, I want to change to fully synthetic, is 5w40 better than 5w30?
car is a C70 T5 1999 model!

Thanks

[t5 stealth]

just hold a tape measure across the centre of the disc,
look square on to it,you will see the edge to edge measurement will be 280 or 320 etc etc.