Re: Mechanical fuel pumps
Your concern about "load" is unwarranted. "IF" you had an engine on a dyno with a mechanical pump , ran it and then removed it in favor of an electric pump , you"might" see ONE hp difference. "Most" non racing , mechanical fuel pumps will NOT maintain 6.5 PSI at 6,000 rpm on a 300 hp engine. The fuel demand is higher than the VOLUME of a standard pump. That is why race engines use larger ( 3/8ths up to 1/2" or larger) fuel lines and high volume pumps , often with an electric fuel pump at the rear of the car.
Relating a fuel pump to an oil pump is not a fair comparison. Different fluids , pump styles , and drive styles.
Experimental Ford parts collector.