Criticism #1 of this oil: "it's on the thin side". Which means its viscosity is formulated at the lower end of the scale range. OK, then. Using only Mobil1 products, what volume of higher viscosity M1 would you add to 5w-30 M1 to get an oil with a viscosity at the high end on the 30 weight scale? Shoot for 11.3-11.8. Use a 6-quart final volume as typical. Example: 4 quarts 5w-30 + 2 quarts 0w-40. Bonus points for anyone who can actually calculate the final viscosity, if it is possible.