To be clear, the mileage I was recording dropped by about 2-3 mpg when I installed the Kelly A/T tires from the old Primewell highway tires, last couple tanks before I reached 10,000 miles in my log were upper 14's to low 15's. It ain't pretty.

1989 Dodge Raider V6
2001 Jeep Wrangler 4.0L
2008 Toyota 4-Runner SR5 4wd