So clock reading minus 10%.
This seems to be pretty much the same across the cars in our family, V70 D5, Golf IV 2.0l TDI, Fiesta 1.2 Style petrol, and of course the T2 3.0l.
When swmbo picked up a NIP for doing 79mph out by Tadcaster in the V70 and told me she'd been trying to keep it to...