We were between well pumps for about 6 months last year, and I hauled water
in a 125 gallon plastic tank 3-4 times a week from the Water Wagon to my
house, about 25 miles.  That's 1000 lbs sitting where the middle bench seat
should be.  BFG All Terrain tires and kept a safe stopping distance, it
actually rode very well.  Still, I wouldn't do it with the baby in the car.

Water Wagon serves Fairbanks folks who have indoor plumbing but no well,
and work off a large water storage tank in their basement or buried in the
yard.  My place is set up for both.  Most of the WW clientelle drive F350
crew cabs with 300+ gallon tanks, and I enjoyed turning heads by pulling up
to the vending pump, dropping 5 quarters in the slot, bringing the hose in
through the sliding window, and filling up without exiting the van.  That
was critical during mosquito season!  But the guy who had a tank the size
of mine crammed into a Suzuki Samurai impressed me most.

I had the water tank in our 94 Toyota pickup sometimes, and it really got
pushed around by the load.  Much more noticeable than in the van.
Especially if the water tank was not full (when I ran out of change), that
would jerk the truck all around once it began sloshing.

Volume-wise, I bought a sofa, loveseat, bureau, and two shelving units from
my former boss in New Mexico, and fit it all in the van in one trip.  Plus
the wife and three 70-100 pound dogs.  My boss doubted I could do it, and
when he saw it done he said he was glad he hired me for spatial data
analysis.

Cheers--
Chris Wyatt
'87 Syncro GL
Fairbanks, Alaska