Upon their introduction to revenue service on 7 September 1936, the Wairarapa railcars became the second successful class of railcars in New Zealand, following the introduction of the Midland class three weeks earlier. The Wairarapa railcars immediately slashed running times between Wellington and the Wairarapa, and would operate the full length of the Wairarapa Line from Wellington to Woodville, and then utilise the Palmerston North-Gisborne Line through the Manawatu Gorge to access Palmerston North. They proved popular with passengers, fully replacing a locomotive-hauled carriage train known as the Wairarapa Mail in 1948, though local mixed trains continued to operate.