I am developing a line follower robot and I am not sure about how many motors should I use: two or four. I'm thinking of using four, but I do not know if it's worth it (it will let the car be heavier, consume more power...). Does anyone have an idea? I'm planning in use something like this design here, of Aniki Hirai: http://anikinonikki.cocolog-nifty.com/.shared/image.html?/photos/uncategorized/2014/11/19/cartsix04.jpg.
The engine I'll use is a micro-metal motor, from Pololu, just like in the link: https://www.pololu.com/product/3048.
I know the question is a little bit vague, but I don't know another way to ask this.