We have all been told for years "HV/HP oil pumps rob horsepower and are not needed". Well, Engine Master just killed that!!!! They used stock Melling oil pumps, Stock, High Pressure, High Volume, and a race Billet (Milden) one. The only pump that lost HP was the race Billet pump. That's right, the stock Melling High Volume pump increase volume (4.9 vs 6.2 gpm), increase pressure at idle 18 psi over stock pump (31 vs 49) and 22 psi at peak flow (54 vs 76) over the stock pump and didn't use anymore horse power.
Conclusion, you may not need anymore volume or pressure a high volume oil pump provides, but it will not reduce the horse power of your engine, so why not use it.
They used a 440 mopar, maybe the test is only valid for that engine. Guess that is debatable.