Just wathed an Australian video about towing with a BYD Shark and its fuel consumption. The Shark has a small battery and IC engine for charging during use. The bloke was towing a 3 tonne caravan and crossing Queensland east to west. He said that his fuel consumption was 24 litres/100km crossing the Divide, but when he got out on the flat country it went up to about 44 litres/100km. He attributed the difference to the lack of regenerative braking in teh flat country.
With that flat country consumption, who could afford to use one of these for towing? As far as I can see, the Shark seems to be a good vehicle, if you are looking to drive a Toorak Tractor.