5 Apr
2022
5 Apr
'22
7:50 a.m.
On 5/04/22 6:36 am, Chris Angelico wrote:
5 L/100km in SI units is 5e-3 m³ / 1e5m. That's 5e-8 m². Or if you prefer, 50mm².
Fuel economy is a unit of area.
This misses the rather important point that it's not just litres of empty space, it's litres *of fuel*. You really need to consider "litres of fuel" to be an indivisible unit that doesn't cancel with a distance. Alternatively, measure the fuel by mass rather than volume. Then your fuel consumption is in kg/100km, which is in far less danger of being cancelled down. Or you could measure the fuel in moles... but then since moles are dimensionless, you get reciprocal distance... Who would have thought units could be such fun? -- Greg