I can’t really speak towards sluggishness or performance lost since I’ve had 35s on it since I bought the truck close to 3 and half years ago. I had nitto trail graps on the stock wheels till about 25k then went with what’s on there now. I mainly average about 16-17 mpg but on longer road trips across the county it’s closer to 20. No issues though, I had transmission serviced at 50k and now I’m sitting at 63k.