So here's the deal ... on motors with significantly more clearances on the bearings, etc. you want a high volume pump to keep those bearings lubed. BUT on a motor with more normal bearing clearances that extra volume isn't needed and so it builds pressure and that opens the bypass. The oil going through the bypass picks up extra heat. Also, as pressure increases so does the load on the pump drive shaft, gear, cam and subsequently the motor. So running a HV pump in a motor that doesn't need it not only puts strain on the parts, it also costs HP to run it. I'd go so far as to say that 90% of the motors using a HV pump don't need it. Just my 2 cents.