Congratulations,
I do not think it is a good idea, the person who wants to fill up the fuel will want to do it quickly and will not wait for the transaction to be confirmed, but you can create an ATM machine so that the person can withdraw from it or a machine for drinks and juices where you can pay with the lightning network.
You can also provide some services and put the Bitcoin logo accepted here, such as changing oil or repairing tires, etc., and with a 5% discount, you will get double interest.
But OP would be investing in more money by putting an ATM, I think that there's not a lot of people that would probably use their bitcoin to pay for such utilities, even with the discount, bitcoin is too precious to be used as a means of payment. The scenario that keeps playing in my head is what would happen to OP's gas station if the prices go down the next day and that next day is also the time for his restocking in supplies, how can he profit if not break even.