Good point Chris with the 70-75% of Gvwr- not only could be unsafe but increasing the wear and tear on brakes, tires, trans, etc
i have a 375 water tank on my 14ft trailer
I NEVER run full- at most ill drive with it 1/2 full- and thats only if the job is close and i want to move quick
If he is buying this big of a truck, I would assume he has the need to haul full tanks.
90%+ of my customers have no access to water, the other 10% its too much hassle to deal with.
Got a call the other day, a contractor promised a guy some cleaning at a large shopping center in town but could not do it because there was not hose bibs 150ft within the area. They actually couldn't find any hose bibs, this guy basically had to leave with his tail between his legs, per say. I already had a full day going, but gave him the number to a buddy of mine that also carries large amounts of water.
In saying this, if you stick to residential or places where water is readily available you shouldn't need to carry much and don't need the vehicle to do it. If you can and do carry anything over 500 imp gallons let your customer know and let them know the benefits as well. Driving a bigger truck and carrying water is a bigger operating expense then those that show up with an F150 and a little buffer tank. You can typically ask for atleast another $5-10 an hour and get it assuming you can sell the benefits of the big truck.
Keep this in mind as well, big trucks = bigger costs when it comes to fuel and maintenance. You make all your money with the bigger truck driving to a site and parking it in one spot for the day and working. Driving around a couple hundred miles a day in a big truck will hurt your fuel bills and of course things like tires, brakes, ect.
The C5500 can be very expensive when it comes to things like brakes, just a heads up. One of my customers has one of these for a service truck and just did the front pads and rotors, and the price for the parts were $1200-1400, not including labor. Where as my tandem axle freightliner is $500 for new shoes and labor all around, or all 6 wheel sets.
Just trying to give you info on experience here, thats all.