20mm clearance with the TD Imola 8x18 ET35 
i use Michelin SuperSport 215-40/18, 215 because i would like to have a tyre protector for the wheels, and keep confort compared to 35.
The rears are hard to adjust because :
The left you have not enough place but you can do it but be patient ! lol
and for the right you need to disassemble a plastic pieces to have access 
It's not difficult but need to remove the wheels it's easier for the lowering.
for ascend the rear you can do it with the spring on the car but only to the half of the ring after it become harder and it's easier to do without the spring.
But if it's for a lowering you can do it with the springs easely.
