I have a 2014 Passat Estate that I tow a caravan with. The manual says that the stop/start should be off when towing, but doesn't say why.

I contacted VW for more explanation, and all they said was it's due to the extra weight and load that the vehicle is pulling. That doesn't make sense to me as the vehicle is stationary when the stop/start is working, so the extra weight and load makes no difference.

Can anyone explain further?