Friction and gravity still apply in related terms regardless of the scale with equal drag and weight distributed relatively... basically neither can be counted as a factor of bias towards one scale or another

The only factor that might be considered biased is the road the cars are running on. the pebbles, potholes, and debris you run through remain a constant shape and size, and being that larger wheels mean a better contact patch, you might say that the road favors 1:1 over 1:10. Not in all cases, but most... just my 0.02