
Wikipedia seems to favour 'hubometer' but I prefer the longer version simply for the way it sounds. My Concise OED doesn't give either.
So where does the stress fall in 'hubodometer'? Probably on the third syllable (following the pattern of 'odometer') but possibly on the first. And possibly either, as with 'necessarily'. At least, I hope that's the case.
And what does 'hubodometer' mean? Well, when a word amuses me this much, I don't really care. But if you must know, it's an odometer (mileometer) fitted to a semi-trailer axle (for example) to measure the distance travelled.