I am currently looking at buying some 33X12.5R15 tires. My question is how much more roll resistance is there from some BFGoodrich All-Terrain T/A KO to some Goodyear Wrangler Duratrac? And how much of a fuel economy drop will i see between the two tires?

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2003 Ford Ranger Fx4 OffRoad 4x4 4.0 L
4" Superlift suspension lift kit, 3" PA body lift, 33x12.5r15 Goodyear Wrangler Duratracs,15" AWC Soft 8 Black Steel Wheels,Superlift heavy duty front drive shaft,Cherry Bomb Glasspack Muffler Dumped, Air Box Mod, Blinker Mod,Temp. Gauge Color Mod, Custom Headache Rack, Custom Front Bumper