Mystik is a good oil. It has high detergency and similar additives as some of the other HDEO's for diesel engines. The fact that it is SL rated tells me that it has less friction modifiers in it (like SM-rated oil contains). so that allows it to be used in an ATV with a wet clutch design. It always cracks me up to see those who use regular "car oil" SM rated in their ATV or motorcycle and wonder why the clutch burns up over time faster than it should. It is because the SM rated oil's extra friction modifiers allow the clutch to slip too much.
I'd have to see the sheet but as long as the 10w40 ATV oil has the proper amount of detergents, then I'd probably give it a try in a car or truck.