Tell your FIL to get more data points. I have lived in 4 states as an adult. My experience says he is dead wrong. Besides, we were discussing PA vs TX taxes, not MI.
A gallon of gas has an additional 38.7 cents a gallon tax in PA than TX. 25.12 cents more in MI than TX. Using a modest 15k miles per year and 20 mpg, that is over $188 a year in additional gas taxes in MI and $290 more in PA.
Using median incomes for each state and the IRS standard sales tax deduction rate of 17% of gross income and the median property taxes for each of these states, grand total is Michigan with a tax burden of 8.57%. Pennsylvania with a tax burden of 7.82% and Texas with a tax burden of 4.64%. This is an annual difference of $2671.54 comparing TX and MI. More interestingly, the median Texan earns a whopping $11,531.54 more after these taxes than the average Michigander. Even adjusted for a lower cost of living in Michigan, that would be $8293.61 more per year for the median Texan. Gotta say it...Don't mess with Texas.