😅Exactly why I've come to the conclusion above. It was my boss's idea, said the dealership told him it would be cheaper and easier to get. Just fine for our use. Hours of research later, I'm coming up with different results, and that's okay. Boss really doesn't care much either way. Can't trust dealerships too much I guess...I really think you are trying to save money in the wrong place. Buy a superior oil run 25 % longer on your oil change there's your savings. Equipment is too expensive to run bargain oil.
I honestly doubt if you will notice any difference in money out of your pocket or your boss's pocket. Between running cheaper oil changing it more often and running a higher quality full synthetic and get running a little longer between changes.
Mowing grass, especially fast, is hard on any little gas motor don't run cheap oil in them.
If this is a real business you care about TCO total cost of ownership and operation. You don't worry about what one individual expense is.