I noticed lately at my local WM that the price difference between M1 EP synthetic oil vs. M1 AFE synthetic oil is only a $2 difference with the M1 EP (on rollback often) ... Even if I ran a typical 5K mile / 6 month OCI in a suburban commuter vehicle seeing 70% severe duty - why would I lean towards using the cheaper (by $2.00) jug of M1 AFE vs. springing for the M1 EP synthetic oil ($2.00 more M1 EP amortized over 6 months comes out to $0.33 cents more per month than M1 AFE) ?