Math Puzzle: The Giant Soup Can of Hornby Island

I measured the can ratio height: diameter= 3.5cm : 2.4cm( approximately)

the length of the tank is about 2.5 times as long as the bike. The regular bike is about 180cm long. 

So, the tank length will 180*2.5=450cm.

Then the length: diameter ratio of the tank will be (450/diameter)=(3.5/2.4)

the diameter of the tank=308cm.

Therefore,

the volume= pi *(308/2)^2*450=33510708cm^3=33510L(approximately)

my student bird just wants to get everything a precise number. My teacher bird just wants to get good reasoning if it makes sense.

Then I did research about the fire tank: 

On this pumper/tanker fire engine, the primary water tank is inside the vehicle, it holds 1,000 gallons (3,785 liters) of water, and it runs down the center in the rear of the truck. A drop tank is like a big aboveground pool that can hold about 2,000 gallons of water.

So my conclusion is this water tank about 10 times of the primary water tank and about 5 times of drop tank, so it can hold enough water on an average house fire.

I want to extend this puzzle by asking: how much paint we need to use to cover the tank in one color?

The surface area of the tank is SA=pi*3.08*4.50=43.5204m^2 since both ends don't need to be painted.

If we get the Dulux from retail, you need about 1 can of paint, including waste