Rotella T6 high oil consumption. I have two Kubota tractors and one with a Mitsubishi engine. Kubota never burned a drop using an old formulation of M1 truck and suv. Ran out of it and started using T6 5w40 and now all three burn about half a quart. I have put 5 hrs on the latest one and it has lost 1/2 a quart. I am attributing this to volatile boil off. Anyone else noticed this? The latest change was the 15w40 with no change in consumption rate. No signs of burning oil. All three are indirect injection engines.