Engine Cells are devices created by Dr. K to power the RPM Rangers' equipment. The Engine Cell Chips are inserted into the miniature Zords summoned from the Rangers' suit logos to restore the Zords to their full-sized form.
These are also used to power the Nitro Blaster. No Nitro Blaster can function in 'blaster mode' without it.
In addition to the twelve unique Cells for each Zord Attack Vehicle, there are special versions for morphing (each type of morpher uses a different type of Cell, as shown below), as well as a checkerboard-patterned Cell for the Wheel Blasters.