excessive oil comsuption on 2007 Chevrolet Suburban 1500

brought new every 400 miles 15% is burning oil no leak engine sounds like old car now is 38000 problem is worse.

1 answer
sounds like you may have a broken oil control ring on a piston or some other issue. that a lot of oil in a short period.
i would have a shop do a wet and dry compression test to verify.

Roy