No NORMAL engine will use a litre per 750miles, however the manufacturers will often put that criteria in as a bit of a get out clause for engines that dont quite meet tolerance.
I change the oil in my cars every 5000miles, the Avant is 12 years old and has done 130k, i never have to top it up between changes. Ok it might not still be at maximum after 5000miles, but i've never seen it below half on the dipstick. My saloon has a freshly rebuilt engine which has done about 5000miles since rebuild, and it too doesnt need topped up, because it was run in properly.
Our previous A4 had 195k on the clock and it did burn oil, approx a litre per 2000miles.
Engines which have been "babied" for the first couple thousand miles will typically have poorer ring seal and more oil consumption than those engines that have been driven hard from the get go.