I have a camplite 5.7 on a 2012 Toyota Tacoma. It's a pretty bare camper, without any propane, heat, or air conditioner. I also replaced the electric refrigerator with an ice box and modified the step by the bed to stow a porta potti. I first tried the unit with a 4cyl regular cab tacoma automatic, with an extra oil cooler, a sway bar, tork lift camper mounts, and a rear sway bar. In spring 2012 we took it on a trip of about 3000 miles, from northern michigan south through the blue ridge mountains in N. Carolina, Virginia and back. The truck handled everything fine, including the mountains, except it was very underpowered in some situations, such as on long hills on the freeway. After the trip I switched trucks for a new 2012 Tacoma V6 auto with towing package. I transferred the tork lifts, air lifts, and sway bar to the new truck. In fall 2012 we took another trip of about 8000 miles from N Michigan to Nova Scotia and back through Ontario, upstate New York, Vermont, New Hampshire, Maine, and New Brunswick. We travelled mostly on two lane paved roads, but did some expressways and even some dirt roads in N. Maine near Baxter State Park. There were some steep long climbs and a couple of ferries included. The rig handled great and had plenty of power. I know that I am close to or even slightly above the load capacity for the truck including my wife and I gear, so we are careful about packing and weight distribution. We averaged 15-16mpg over the whole trip. One disappointment was that the rig was a few inches two high and a few inches too wide to enter Baxter State Park. Next time we'll be better prepared to leave the camper in a nearby campground.