Nope, the Ducato/Promaster is not the same as the Transit chasis.Different chassis. The chassis is based off a Fiat from what I know.
Unless the sprinter is based off a fiat (doubt it since sprinter is rwd)
They don't put max capacity stickers on the inner door panels for no reason. the load is so specific that if you go over weight you can affect the suspension ans the tires as well. you might get a way with it for a bit but when things start going wrong you'll be the one paying up.I have this issue every year with the rear traction. It's funny because too much load weight can actually cause a loss of traction believe it or not. but I only experience this when I exceed the load weight capacity in the rear. It has to be with in the maximum carrying capacity.
I have always had this concern and never realized till one transport trucker told me about it at the truck stop. We were talking about service and warranty on our vehicles and he brought it up. He mentioned the first thing to noticed is the tires for uneven wear.They don't put max capacity stickers on the inner door panels for no reason. the load is so specific that if you go over weight you can affect the suspension ans the tires as well. you might get a way with it for a bit but when things start going wrong you'll be the one paying up.