Originally Posted By: Swift101
So there would be 0 benefit using EP since my OCI would just be 5K?
Possibly. IIRC, the primary difference between the two is the EP having a more robust additive package that holds up longer. A motor oil is always the sum of its parts. While EP touts itself as a 15k oil, a turbo is a more stressful environment and tends to breakdown an oil more quickly. So if regular M1 is somehow getting beat up too quickly for your tastes, the more robust additives in the EP might add a little more OCI before breakdown.
The only way to be sure is to run some UOAs. But for street use, unless this is a seriously modified engine, I'd be surprised if regular M1 completely fell apart in 5k.
The honest truth is, as long as it meets the viscosity and approvals/certifications recommended by the engine manufacturer, and you are not subjecting it to unintended applications (tracking, etc.) you can run ANY oil in any given engine, right down to the cheapest no-name conventional. The issue is for HOW LONG, with increasingly better oils allowing increasingly longer effective service before they start to deplete and breakdown. But obviously, you don't want to be changing cheap oil every couple thousand miles.
If this is for the Hyundai in your sig, the manufacturer's preferred choice is 5w-40, with 5w-30 only if 5w-40 is unavailable. Not a lot of manufacturers in NA currently recommend a 40, which suggests that this is an engine that requires a more robust oil than most.
If 5w-40 is off the table, have you considered M1 0w-40, which is a more robust formula than either 5w-30 variety, and is a light 40.