Mike, I've never used Mexico's aeronautical charts, so I have no idea how accurate they may be. When I consider how long Jeppeson goes between issuances of approach plates and enroute charts I would consider Mexico's own charts may be out of date as soon as they are issued. I am not attempting to demean anyone down there by saying this.
I always have used World Aero Data's Mexico webpage for flight planning and fuel.
http://worldaerodata.com/countries/Mexico.php Even when I use this, I try to get independent confirmation by telephone when it comes to fuel availability. Some parts of Mexico (like Baja for example) are at the end of very long supply lines, and they can often run out of fuel without notice. Case in point: If the fuel truck has a flat tire around a religious holiday, it might take the driver 3-4 days to get it repaired and back on the road. This is how Mexico operates. The clock is not a concern... the calendar is.
Bottom line: When in doubt, call ahead.
Hope this helps, and good luck Mike.

RC