"We must be the only city in the world which has electrified its network and then run the brand new trains slower than what existed before - which is already too slow," he told the Herald.
"This is especially bad considering the new trains have much faster acceleration and are meant to be better suited to our tracks."
Conservative settings on a train collision protection system after the first electrics were introduced to the Onehunga and southern lines a year ago led to complaints by drivers that they were being over-ridden by the system's speed controls.
Although settings have been adjusted to let the trains get closer to their top permitted speed of 110km/h, compared with the diesels' maximum capability of about 80km/h, the western line presents challenges because of its numerous stations, level-crossings and curves.
An Auckland Transport spokesman said further run-time testing would follow the bedding-in of full electric train operations from July, leading to timetable improvements later this year. He said next week's changes were to ensure trains could meet allocated time "slots" at Newmarket Junction and Britomart.