"Minimalist" slide-in truck camper that won't kill my MPG?

[Regcabguy]

Consider a family built used Northstar. Well made,not that aerodynamic and can be had for a fraction of the Four Wheelers. The bucks you save will more than pay for mileage reduction.

 

[STANG302]

I am leaning towards something like the Rayzr. There light on weight and the wallet. And have enough creature comforts to make life easier.

http://www.truckcampermagazine.com/news/tcm-exclusive-2016-travel-lite-rayzr/