Hugo Nebula wrote:
Reading car forums, the overwhelming opinion is that a pressure washer
is needed to wash one's car properly. So I went and bought a cheap
Halfords one, complete with snow foam attachment. The results were
disappointing to say the least.

I know it's not a mega powerful one, but I was amazed at how low the
pressure was out of the nozzle. I was certain my hose gave a more
powerful flow, so I did an experiment and timed how long it took to
fill a bucket, and therefore what the flow rate is from my tap. It
amounts to 1,000 litres per hour, nearly three times the flow rate of
the PW. Some of the best pressure washers only appear to give half of
that.

flow rate is not pressure.


Am I missing something here?

yes.

Is pressure a function of the flow rate,

No.

and if so, what's the point of a pressure washer if it gives less than
mains pressure?

since it isn't so, think again.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.