Ha sorry I indeed failed to catch your irony... My bad too, then. I'm actually quite interested in the fact that any equation can be "sanity checked" by solvin

Ha sorry I indeed failed to catch your irony... My bad too, then. I'm actually quite interested in the fact that any equation can be "sanity checked" by solving it for units only (without values). It's always handy to make sure I didn't forget some exponent here or there. And knowing extended units as a composition of fundamentals (some variation of mksa) is kind of entertaining intellectually.(e.g. Newton = m.kg/s^2, which really makes sense when you think about it). Going down to Planck units and their significance in this universe (discrete spacetime manifold? Is reality ultimately non-continuous?), and here I am wishing our conventional units (of time, distance, all) were integer multiples (e.g. Decimal exponents) of Planck units. But I'm digressing, aren't I. As far as fuel and efficiency goes, I'm not much of a car person. I didn't know that mpg was used outside the US, that's an interesting historical artefact.