Also depends on the condition of the door. The person who painted mine before me slapped paint on with a brush and it was full of brush marks. I ended up with 180 then 240. Loads of high build then 400, using a DA. That after 2 coats of top coat i moved to hand sanding with 800, 1000, 2000. 2000 bit pointless as the body isn't super straight and dint free.