Holding Tank Sizes
The Citation Sprinter by Thor has a 40 gallon freshwater tank
Which Sprinter RV has the largest holding tanks? Also, what size of holding tanks is best for boondocking up to a week?
The size of the holding tanks you need all depends on how much water you use per day and how much wastewater goes down your drains. When using water for drinking, cooking, doing dishes, taking navy showers, and flushing the toilet I find that in one week I'll use about 20 gallons. And that's for 1 person.
As for the grey water holding tank, I find that in one week about 7 gallons of wastewater will go into it. However, I do wash my hands outdoors and I take navy showers to conserve water, so not much goes down the drain. I also don't use gallons of water to wash dishes so not much goes down the sink drain either.
With the black water tank, about 6 gallons will go into it in one week. This isn't typical though, as many will fill their grey water tank much faster than the black water tank. This is why grey water holding tanks are typically larger.
So which Sprinter RV has the largest holding tanks? I was curious myself so I did some searching. It appears the Citation Sprinter and Siesta Sprinter made by Thor have the largest tanks. The freshwater tank holds 40 gallons, grey water tank is 38 gallons, and black water tank is 34 gallons.
The average tank sizes for a Sprinter RV are about 30 gallons for freshwater and grey water, and 25 gallons for black water - though a few Class B Sprinter RVs have black water tanks as small as 10 gallons.
A week of boondocking should be easy to do with pretty much any Sprinter RV, as long as you take it easy on water usage. Of course with 2 people you'll have to be extra conservative. Happy boondocking!