i use millers xfs 5w 40, found it doesnt use as much oil using the 5w 40 and I alsoi change it every 6-8000 miles. Noticed a lot of VAG cars have changed from 0w 30 to 5w 30 due to oil consumption. eg the mk5 golf
I think you are just wasting your money on AVS spec oil if you aren't running your car on AVS. I think you are better off buying twice as much of a 'normal' synthetic oil and changing it more often.
The AVS oil just has more additives to prevent oil degradation over large mileages - up to 20k or 2 years. If you are changing it at 10k / every year or better still 5k / 6 months a 'normal' synthetic oil shouldn't degrade.