WOLFSBURG — Volkswagen Group engineers are encountering obstacles as they attempt to shave up to a third of the costs of developing a family of city EVs for the VW, Seat and Skoda brands.

VW Group' Seat brand will lead development of full-electric city cars based on a shortened version of the group's Modular Electric Drive Toolkit (MEB) architecture. They will cost less than 20,000 euros ($22,500) and will replace the VW Up, Skoda Citigo and Seat Mii minicars.

The shortened MEB platform could also eventually be used for electric successors to VW Group's subcompact cars sold in Europe such as the VW Polo as stricter European Union CO2 emissions reduction targets make developing small cars with combustion engines uneconomic.

The smaller MEB platform will be used for cars up to about 4000mm (1575 inches) long.

VW brand development chief Frank Welsch said engineers are looking into radical changes in the EV architecture for the city EVs.

Shrinking key drivetrain components and using less steel, plastics, fabrics or other materials were among options.

The two long banks of battery modules fitted perpendicular to the door sills could be rotated 90 degrees so they fitted lengthwise, Welsch told Automotive News Europe.

"That would give us more space between the battery and the sills, and hence a greater cushion should an accident occur," he said.

"Safety is a major priority at Volkswagen and a lot of money is spent trying to protect the battery cells in the event of a crash," Welsch said.

Seemingly more straightforward measures could be problematic, however.

"We have to see for example whether the range of electric motors we currently have planned for the MEB need to be supplemented with a smaller one for example," Welsch said.

This means adding new complexity into an architecture streamlined to create the greatest possible commonality of parts across the entire range.

Welsch said it hasn’t been decided either whether such a motor should be an induction motor rather than the competing format intended for use in the ID, which uses a permanent magnet that requires rare earths.

Currently VW Group's entry-level electric car is the VW e-Up. Skoda will launch a Citigo EV based on the e-Up this year and Seat's Mii EV will go on sale next year.