Dan Heinemann

May I suggest, along the same lines, for fue savings is GasBuddy The App.    You can set it to find only Diesel or to find  Gasohol which they are still calling gasoline. They also have a "pay with Gasbuddy"   that I have not tried. You have to allow them access to your bank account. Similar to some of the other pay by phone apps. This gives you additional savings.  Like you , I have traveled side roads to get to cheaper fuel, but I use Gasbuddy to direct me, and to give me choices.  While you are waiting for the pump to finish emptying your wallet, you can add your own price update or verification to Gasbudy.  The more we all use it, the better it becomes.

Join Costco and you get their Citibank credit card.  All gas purchases up to $7000 a year get a 4% rebate. In addition a 3% rebate on travel and restaurants, 2% on Costco purchases, and 1% on everything else.  You may not need a 48 roll package of toilet paper, but there are many other things that full timers can still use.   The rebates are worth it in themselves, even if you never shop at Costco.

The same goes for the Sam's Club Mastercard.  The cash back on fuel is 5%, at any fuel station, not just Sam's Club.  By the way, 5% is15 cents per gallon if fuel is $3.00 a gallon.  The cash back accumulates until the January statement, which has a check, arrives then you get real cash at Sam's Club.  This year, my 2018 rebate check will be almost $500.00. 

As mentioned above, Gas Buddy is a must for finding that station with the lowest price for fuel in your area.  It also allows me to "look ahead" to see if fuel is cheaper or more expensive in the direction I am headed.  If cheaper, I'll wait to fuel until I get to the less expensive location.  If that is beyond my fuel range, I'll add a minimal amount and then continue to the best price ahead.  If the opposite occurs, the prices ahead are more expensive, I'll fill up before I reach the higher prices ahead.  I was able to drive through California, from the north on I-5 to the south, leaving on I-8 purchasing only 10 gallons of diesel to get me to Arizona.

I also use Gas Buddy to help find diesel fuel.  One trick I've learned is going to Kroger food stores and using fuel points at their fuel centers.  Not all of their fuel centers have diesel but the ones that do are marked on your Gas Buddy app.  If you have one near you can usually save anywhere from .03c a gallon and if you have caught the store offering 4x fuel points and bought gift cards you can save even more.  I put 35 gallons of diesel in ours for $3.64 total at one stop here in Nashville, TN.