You need basically every gas discount card you've ever heard of
Start out with chase ink bold/plus and buy Shell and BP gift cards at Office supply stores for 5UR/$. When you don't have anything else you can use it for 2Ur/$ directly.
Get Discover and Chase Freedom for both you and your spouse if you have one, and use them up till the gas limit for 5% back during the quarters where that applies. Get the Pennfed cash rewards for 5% and Costco Truearnings business for 4% up to their limits.
Finish up with something like Barclay's arrival or Fidelity Amex at 2.2%/2% to cover when you've capped out all other cards (which you will at 120k/yr on fuel if no spouse).