...i was not sure if you said 12 in. or 12 ft . ? ...but a dual cell with stock clone motor and red gears a 12 in. run went 1.24- seconds......And a 12 ft. run took 5.63- seconds.....i'll do some more cars 2 nite !...
...this was done on my kitchen carpet its not to thick but i might even try at work 2 and see how it does on a smooth surface....