I have a Golf GTI Mk7 with a just over 150K miles on the clock. It has always used a little oil (as my last Mk5 GTI did) , however recently it has become completely excessive. Over the last couple of weeks I've been adding around 0.5 Litres of 5W/30 oil around every 300 miles !! - The engine runs perfectly, smoothly and feels just as powerful as it always was. Also there's no smell of burning oil and no obvious blue smoke.. I recently did have an oil leak from the sump and I had a steel sump fitted, so there now are no obvious oil leaks (you previously saw a drip of oil on the driveway - now there's nothing). I'm confused - it runs great , gets great mpg on a on long run , but eats the oil. I know it's got a high mileage - is it just just needing new piston rings, valve seals or should I change the PCV valve system. There are no obvious oil leaks in the engine bay,,,, any suggestions welcome..