almcc wrote: "Our MC works almost 100% of the time with the zip code work around except for a couple of stations in the "boonies" where nothing works at the pumps, including debit cards."
We have a BMO US$ MasterCard, and on a recent 5-week trip to the States, the MC worked 100% of the time with the zip code work-around. For those Canadians who are unfamiliar with this "trick", here's an example:
Say your Canadian postal code is K3F 6Y4. Your "zip code" would be 36400.
Regarding Costco gas bars on either side of the border, remember to have MC in Canada and VISA in the US, as Costco gas bars aren't equipped to take cash. Or, as I mentioned in an earlier post, if you don't have the correct card, simply go into the store and buy a "Costco Cash Card" which will be fine at the gas bar.