A Givealittle page set up for the cause had raised $7500 while the tally, including money from donations, was at $585,000.
This afternoon's drive from Raetihi in the central north Island to Whanganui was about 102km for the team which included expedition leader Al Fastier and co-ordinator Lydia McLean.
The tractors had been moving at a steady but slow pace of 20km/h and while there had been a few unplanned stops for "minor" mechanical faults, Watson said it was nothing team mechanic Brian Blyth couldn't handle.
The stops so far took in Sir Ed's hometown Tuakau, Hamilton, Otorohanga, Te Kuiti, Taumarunui, National Park and Raetihi.
Watson said the expedition called on Kiwis to "Give a fiver to the driver", because Sir Ed's face graced the New Zealand $5 note.
"We've been overwhelmed with the support on the road. People are stopping them to donate to the cause.
"We've been really delighted with the support on the ground."
Watson said if members of the public can't make it to a planned stop then they can still donate at the Givealittle page at https://givealittle.co.nz/cause/expeditionsouth
For more information about the trip including the route, a blog and the current fundraising tally visit www.expeditionsouth.co.nz