As the gas taxes go up and the gas i use for the OPE becomes more as I drive less, I looked into getting a state tax refund on the gas I use. Seems all I have to do in Illinois is keep track of what I buy and how it's used. Pretty simple as the mower gas I always fill up separate from the cars anyway. Of course there's the 4 page form that needs filling out....
https://tax.illinois.gov/research/taxinformation/motorfuel/mfrefunds.html
https://tax.illinois.gov/research/taxinformation/motorfuel/mfrefunds.html