I think that we are going in circles. My understanding of the issues involved may not be as much as they could be, but I think that the above statement is a bit curious. The full output of the 175 is obviously higher than that of the 135. Now if the 135 could put out the same capacity at 2400 watts as the 175 did at 4800 watts, I'd see your point. But the 175 is putting out greater capacity at full output than the 135 is able to put out at its full output.

My initial comment was based on 220V drawing lower amperage than 110V for the same output. Granted, the overall effect may be limited depending on conditions, but the 220V load is already balanced and as such is more efficient. Going to 3-phase allows you another level of efficiency.