The members here are an erudite and knowledgeable crowd, so I thought I'd as a question that's been perplexing me for ages.
Here in Europe we largely use the metric measurement system. In this we have length (metre), weight (gramme) and volume (litre) along with various multipliers. These are among others deca (x10) kilo (x1000), milli (x 1/1000)centi (x1/100) and so on. Hence we have 1000 grammes = 1 kilogram, 1/10 litre = 1 decilitre and so on. Allmost universally these are pronounced as multiplier (brief pause) measure, as in centi-meter,, kilo-tonne, milli-litre.
Now we come to THE question - why is the kilo-metre pronounced by (mainly american) people as kil-ometer? After all we do not hear mill-imeter or kil-ogram. Is it because we were used to having speed'ometers, gas'ometers, ped'ometers and took the pronunciation from these common measuring devices? Now a kilt-ometer, that's something else again!

Over to you chaps...