well if you wanna save ure tyres, you have to wonder why u got coilovers. Coilovers would suggest you want good handling, and therefor like a bit of speed im guessing. the degree of camber gives you better cornering, but ure tyres are gonna wear quicker.
If you wanna save the tyres then you wanna reduce the camber so you have more rubber on the road to start with.
I think thats right.