Another gearing question...

[Shiftone]

I'm just getting into Oval racing and was trying to get my head round gearing choices.

I run brushless 13.5 blinky 1S.

After a few weeks of getting use to my car and racing, I'm using a 45/16 gearing for a rollout of about 54.7mm/rev

My question is how does total tooth count effect the car when rollout remains similar? For example if I use 51/18 for a rollout of 54.4mm/rev - aside from being a fraction slower what are the repercussions?

Thanks in advance.