i'm told they changed the conversion rates to miles from kilometers
amex reward ratio is now 1000 points equall 1000 miles (it used to be 1,600).I'm told they made the change without notifying amex.

similar ajdustment to hilton. now 5000 mexican miles equal only 10,000 hilton points. for all those peole like me trying to get the 20,000 hilton points for next to nothing:even if you have some real miles in your account, only the miles portion of the account (no internet bonus points,amex rewards points etc) will transfer to hilton.
This is very misleading if you ask me. Hence, you cannot fly one sky alliance flight to get mexicana miles and then transfer your entire mexicana account to Hitlon-they will only let you tranfer the air miles portion only