Sure it will, there was a trick posted very early that i have used. Take any card you have without a magnetic stripe and insert into the card reader. Then fire up your Samsung Pay and while it's still vibrating or pulsing, hold it very close to where you pull out the card and it works. For these gas pump readers to work you have to insert some card to trigger the magnetic head to start to sense. Of course, most newer gas pumps have a contact less reader on the pump itself. On those, the very first thing you need to do is fire up your Samsung pay and hold your phone right next to the reader prior to even selecting grade of fuel.
On another note, I'm a bit disappointed as i just redeemed 5000 points for a rewards debit card that failed to load on my phone either via wifi or 4g cellular (got confirmation email though). Used the "more" option to "add rewards card" and getting the dreaded " Unable to add Rewards card. Contact customer service" message. I am now dealing with Samsung Pay customer support to resolve with no ETA.
Sucks.