Well, i tried Shell Helix Ultra 5w30 for my last oil change instead of the usual cheap Tech9 (i guess it's our equivalent of SuperTech) or Total Quartz 5w40. Usually at the end of a 8/10k kms oil change interval the level is below the middle on the dipstick. This time it is right on the middle after only 3000 kms. Is it normal to burn that much more oil with not that big of a difference in viscosity ? I always fill the engine close to the max level which is exactly 5.5 liters. In my experience so far, synthetic 5w40 seems to be the best to avoid consumption. The M111 engines i had all seem to consume more oil with 10w40 and 15w40 but i didn't think synthetic 5w30 would burn off that fast. 70% of my driving is highway between 2900 and 3300 rpm. Should i try 5w50 to decrease oil consumption even more ?