Sorry mate a bit of both. Places like pembrey (real grippy tarmac and point and squirt layout) will eat tyres. Where as silverstone is not to hard on tyres at all. I have also had no probs at mallory even though it,s tight.
And just to confuse matters i did 2 days at cartagena on Dunlops and they where awesome hardly a mark on them yet i put a brand new set of pirelli slicks on for the 3rd day and the rear self destructed in 20 laps it not only looked awefull but it was sliding on a couple exits and not very stable mid corner !!!
So i guess there is no equation that will predict tyre wear all you can do is get a good base setting for your suspension then get out and ride. Try a few differant makes and when you find one that you like stick with it.
Dunlops for me