Hi all. Changed my oil in June and thought i'd give Castrol GTX magnatec a try. It was quieter when i started it up and ran smoother so i was pleased with it. The best thing though is it seems to have slowed my oil loss considerably. My 156 used to drop 1/2 the min max range on the dipstick every 3 weeks (800 miles), now it drops the same every 2 months, so seems to have slowed it down.