FLOORING: Concerns about tiles expanding and contracting?

I went with VCT tiles, however others here have noticed the gaps getting bigger with temperature change, however so far mine look fine.

I cut mine down to 9x9 inches for a couple of reasons,

1. the original tiles were 9x9 inches
2. the smaller area looks better with smaller tiles.
3. a smaller tile will contract and expand less than a larger tile. to explain this just for arguments sake
lets say a 12x12 tile can expand contract up to 5% of its size, 5% is more area of a 12x12 tile that 5% of a 9x9 tile make sense?
if you look at all of the lines between the tiles, with more lines between the tiles from smaller tiles each line will have less of a gap. not sure if I explained that very well.