I came across a youtube video last night which outlined how to calculate how much h2 gas is required to run a car ( based on btu calculations), the author came up with a simple formula:

10,470/mpg = x L/min of H2 gas

example

a 30mpg on petrol car would require

10,470/30=349 L/min of H2

https://www.youtube.com/watch?v=7qzrI20VPCw#The maths looks sound but there are a couple of variables not considered in the video

1. burn rate of H2 is different to petrol

2. mpg rate will be same using petrol or hydrogen

3. HHO is used generally, rather than straight H2

Looking at point 1:

Burn rate of h2 is about 5.5 times petrol since Stan was adding combusted exhaust back into the hho stream to lower the burn rate, I would assume

that would mean less H2 ( as hho) is being used than pure H2. That would lower the L/min

required. Would it lower the L/min by a factor of 5.5?

So instead 349L/min in example above ( divide by 5.5) gives 63L/min?

Point 2: I have no knowledge on this, I would be guessing that hho is more efficient due to

smaller molecule size .

Point 3: I have no idea how using hho compared with straight H2 will effect amount of gas required