marque, I understand what you are saying and some good points made.
but in my opinion all things considered, if the engine is constantly using 1 litre of oil every 800 to 1000mls then this is unacceptable, and would merit investigation.
I feel your pain :-(
If you take you car to mini and say this to them, they will tell you 1 lts every 1000 miles is normal. If you insist it is not correct they will investigate if tou push hard enough and charge you lots for no fault.
If you go to an independent garage who noses nothing about minis you will have a huge bill and the same engine with loads of new bit with the same problem.
but if you want to reduce the oil consumption, like I said fit a catch tank or oil separator system this will solve lots of problems short term and long term if fitted properly. it's a known problem on the mini engines has been for years. It's the way the get the engine emissions, some cars are worse than others
It's a real pain but really the only way to do it if you think it may cost you £100 for a catch tank and you think och.
just think if you were using 1lts every 1000 miles and a litre of castrol edge 0w30 fst is between £14 an £18 it does not take long to add up and over the bmw specified service interval, the catch tank is going to pay for its self and you will have money left over don't need a accountant to work that one out.
Unfortunately that's the fun of these cars and the regulation.
What gets my goat is they phased out the good old two stroke motor bikes because they are not good for the environment. Well 1 lts of oil every 1000 miles your nearly in two stroke territory anyway that me finished yapping of to ride my stinky old two stroke :-)
Just as a note if you fit a catch tank and its still using a lot of oil it could be lots of things such as piston rings, valve stem oil seals, turbo labyrinth/magnetic seal, engine getting to hot due to bad cooling or oil system, bad head gasket and the list goes on
Take care all kept you oil clean and topped up :-)