I like my 20-50 vr1 for the car, the 4.0 got 10w30 dinosaur oil. I think the synthetic thing is a market tactic. Yes, is supposed to last longer w/o thermal breakdown of viscosity, but it's still dirty after 2500 miles. . Just an opinion Sir
And the non synthetic oil is the same dirty after 2500 miles. So which oil do you want at 2500 miles? And it’s not just viscosity stability that makes a synthetic oil far superior to mineral oil.
