I have an ATM card from JPMorgan Chase in New York. It has the Master Card logo on it plus NYCE,Cirrus and Maestro. Using it in banks outisde the US I have been getting exchange rates about 3.4% worse than the oanda.com central rate. In all cases I am withdrawing funds from my checking account.

Chase swears that they don't charge me any fees since I am a Select customer. I can't understand why the effective rate is so bad.

On my Amex cards I get rates as low as 2% difference up to a maximum of over 3% and I cannot figure out why the variance. On a recent trip to Australia I had 4 charges from Qantas' web site for flights and hotels. 2 were at 2% while the other two were at 2.8% difference - all within a few days, same country, same charging party.

Any ideas?