Pat Naughtin wrote: "Shouldn't we prefer units that have a coherent unit in the denominator in which case L/Mm would become �L/m (that's microlitre per metre)?"
Somehow, I think you'd have a hard time convincing motorists that that's a good idea. On the other hand, if car manufacturers and governments agreed to use that value and, instead of specifying the units, simply expressed it as a consumption factor, it might get accepted. Engineers and other well-informed people (like us) would know what the unit of measure was; others might not even care. Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator]
