Joey,
In general Loco USA sizes are the same as anyone else's USA sizes.
eg I used to wear Brooks 9, I now eear Loco 9.
However Asics in particular you often need to go up a half size.
eg Asics 9 is approx Loco 9.5
However having said that it does depend on people's feet. Some people quote AUS or UK sizes so its not a proper USA sizing. Even then some people might go UP another half size or more. I have no idea why.
So back to the question : if you wear Asics 13 then its likely to be a Caramuba 13.5 which we don't do (all the models go to 13, except Mojo which goes to 15*). However we'd be happy to send you a 13 and refund if its not right or send a Mojo instead.
The best place to ask would be
here surely but how about I send you an email offline tonight ?
(*) The logic is that most people that large will need the slightly heavier Mojo.
Kevin
part-owner LocoRunning Australia