V220 2016 OM651 oil consumption

If anyone has any advice would be appreciated, so it’s consuming around 1ltr every 1000 miles, more if I hit the motorway. New turbo and rocker cover fitted, no smoke and drives absolutely fine. It is high mileage nearly 200k miles. I have been told by couple mechanics it must be the piston rings which obviously pretty much involves a full rebuild. Any advice would be great.