Useless units

The petrol pumps at our local supermarket have been upgraded.  There is now a button that you can press on the diesel pump to give a fast delivery.   You unhook the nozzle, press the button and you get diesel at the super-fast rate of 5 metres cubed per hour.

This is handy to know if you need to fill a 5 metre-cubed fuel tank; you can do it in an hour.  Or even a one metre-cubed one; you can fill it in 12 minutes.  The time to fill a normal car fuel tank of capacity say, about 80 litres needs a bit of calculation.   I hope you have a calculator handy.

5 metres cubed per hour is 5,000 litres in 3,600 seconds, or about 1.4 litres/second, or say 10 litres in 7 seconds.   So you can fill an 80 litre tank in just under a minute.

A posted delivery rate of 1.4 litres/sec would be helpful;  7 seconds for 10 litres might be even better.  But 5m per hour is useless.