Peco N gauge and Peco OO gauge

OO gauge track would be (approximately) twice as wide as N gauge track.  OO scale is slightly larger than HO scale.  Many British OO scale models are actually gauged to run on HO track.

 

For N scale, I would recommend using Kato track.  It'll be more expensive than Bachmann's N scale track, but I think the Kato track is better made.

 

The Peco N scale equipment should run fine on either track, though.

 

Rusty 

Actually rusty, the mayo track is less expensive that Bachman track at the retail level and given most discount pricing should be less there as well. The Kato track is a far superior and more forgiving product. I've got a bunch of it in HO and N scales and find Otto be a wonderful system. Peco, especially code 55 is a huge PITA