Mine has used oil at a similar rate for 65k since i had the car (i do quite a few motorway miles). I got the car it had 52k on it and is still going strong @ 117k and still using oil with no drips on the floor, so it must be burning it, but runs superb. I wouldnt worry to much about it, some use it, some dont, its not a good thing but keep it topped up and thats that. I use cheapo halfords 5w-40 fully synth, ive tried everything in it as i drive it very hard, even 300v...but it still ate it.
Im 95% sure mines either got scoring on the bores of cylinder 3 or worn rings, as that plug is always blacker than the rest when i change them. However im a sprayer not an engine specialist, but im guessing id be able to find out with a compression test lol.
Mine had a the cams done, belts, dephaser @ k-tec and everything resealed, but still uses it!