About 12mpg avg on a 200 mile trip in tow/haul mode averaging 65 mph
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salsa red DC reg bed.
Truxedo Lo-Pro, bed extender.
Pioneer AVIC-D3 Navi w/ backup camera and bluetooth/ipod controller
Polk Audio 6.5" and 5.25" seperates -mids/highs
Pioneer 10" shallowmount sub under rear drivers
Memphis Audio 4ch and Infinity Reference Mono Amp
Dual headrest 7" DVD system.
H11 and 9005 HID upgraded headlights.
TRD CAI and TRD Sway Bar
Limited 20" wheel/tires combo
about 10 pulling 5K travel trailer up and down hills. about 13 on a flat run.
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'07 4x4 CrewMax 5.7L SR5 - Texas Edition Mods: TRD CAI, Borla Duals, 305/50 R20 Nitto Terra Grappler on 20x8.5 (35mm offset) RockStars, ARE Camper Shell, Bed Rug. CBTMA Member >>> What the heck is that?
Aerodynamics seems to be the big killer on the highway, more than weight. Loaded or unloaded doesn't seem to make very much difference once up to speed on the interstate.
Towed my Travel Trailer 3253 miles and got 11.5 average. The trailer weighs 5700lbs and I have a double cab 4X4 with 4 people in the cab. I even carried 6 cases of water, a 150lb generator, a bbq grill, 2 mountain bikes, clothes for 2 weeks, beer for two weeks and just about anything else you can think of for a trip to the Grand Canyon.