The main changes being a shift in the location of the electrical equipment from under the steps to the back wall of the driver's cabin, the introduction of a separate cabin for the driver, as well as the removal of the small windows under the front and side windscreens.

[1] The most important change was the introduction of motor grouping, which reduced the energy consumption by 12%.

[citation needed] During initial acceleration, the four motors are connected in series, whilst at higher speeds, two groups of motors are connected in parallel.

[1] While in service, the 105Na vehicles were the subject of various modifications and upgrades (including changes in the electrical system, new front plastic, change of the door opening mechanism, and even re-design, for Poznań, to the bidirectional Konstal 105NaDK).

Almost all 105N cars in Poland have over time been modernised to the 105Na standard.