My understanding is that Chase Pay replaces the use of physical cards – in this case, both credit card and Fuel Rewards card – as both card numbers are registered in your Chase Pay preferences (linked CC and merchant “Shell”), @gatorj.
If your preferred linked CC is a MasterCard, you should additionally be able to take advantage of a MC promo offering a $0.15/gal. discount when you register your MC number with your Fuel Rewards card by March 31, 2018:Earn Fuel Rewards savings with your linked MasterCard
…which is in addition to the:$0.15/gal. discount per $100 spent on groceries that you can earn when using your registered MC, or the $0.10/gal. discount per $50 dining, $0.05/gal. discount per $50 travel, $0.05/gal. discount per $50 spend with a linked MC, Visa, or AmEx card, and other shopping offers that accompany the Fuel Rewards card. Support FAQ's | Fuel Rewards Network
View FAQs and get support help from Fuel Rewards Network Member Support Representative.