Quote Originally Posted by NortonDommi View Post
A lot of mechanics, engineers of all kinds have these really neat steel rules with a sliding pocket clip on them that doubles as a measurement stop. Quality micrometers if Imperial ones usually have decimals and their fraction equivalents etched in the frame, some verniers,(nearly spelt verynears), have the same on the back of the vernier frame.
And everyone whose profession involves aviation level quality control knows that every time you do a conversion on a measurement you introduce a potential error. Gimli glider and Mars Climate Orbiter being classic examples of the results of this. see http://www.homemadetools.net/forum/e...rbiter-61787-3

Reading the dimension as .0001 inches or .001mm then converting to 128ths to find you are 1/256th out and converting that back to thous before making your next cut is introducing multiple fail points.

I suspect that you still calculate your cars "fuel consumption" in Miles per Gallon rather than litres per 100km because that is the way your great grandfather did it.

L/Km involves dividing the Km your odometer says you traveled by the quantity of fuel added. One simple calculation, minimal chance of errors.

MPG involves converting the km on your odometer to miles, first chance of failure, then converting litres to gallons, another chance of failure, and then the third calculation to get not your fuel consumption but distance traveled for a set volume of fuel. Then when you have to work out how much fuel you need to travel 625km you need to do a far more complex calculation than just multiplying the fuel consumption by 6.25.

There is an old saying in aviation about the three ways to do a job - the right way, the wrong way and the British way because the British have a single design law - why make it easy when with a little bit of thought you can make it bloody near impossible.