I would guess its blocking up somewhere... have you checked the oil pickup pipe?
How would a blocked oil pickup be the the reason why the OP is using oil?
Using oil could be something as simple as the following...
Blocked breather hoses as the standard hoses collapse over time from the heat and oil contamination. This creates more pressure inside the engine as it's not breathing as intended and can force oil past the piston rings etc.
Worn piston rings. This would allow oil to seep past the rings into the cylinders so the oil will burn off, you should notice this as the car will produce smoke from the exhaust, normally blue and it doesn't smell very pleasant.
Valve stem oil seals. Again this would be noticeable through smoke from the exhaust.
An external leak such as rocker cover gasket, sump gasket etc check for leaks around the engine.
I have noticed on previous cars I've owned and not necessarily cared about that some cheap oils tend to be consumed more, also old engine oil that hasn't been changed in a while tends to burn off quickly. Try using a quality oil or give it an oil change anyway. These engines use 5w30 or 5w40 fully synthetic.
A blocked pickup would cause oil starvation. early signs can be the Vvt rattle on startup as this relies on oil pressure to operate. On the other end of the scale the engine would knock and sound tappy along with the oil pressure light illuminating which would result in engine failure.
A blocked pickup would have no affect on oil consumption.
There is normally a little mesh that sits in front of the pipe and that is known to block up easily on the 1.8T engine, think the R is worse than the 180. When you drop the sump it should be pretty clear if the mesh is blocked or not.
This
guide should cover everything for you
The oil pressure
problem due to a blocked pickup affects all 1.8t engines that haven't been serviced regularly. Not just the cupra r range but all VWs Audis, Skodas and Seats fitted with the 1.8t engine.
In fact audi were worse for it as they put all there cars on long life service plans when the 1.8t was first introduced. It wasn't long before people were having problems so they reduced the service interval.