Don't get us wrong, we enjoy burning up gobs of those precious fossil fuels just as much as the next guy, but a cross-country road trip in a hugemongous RV for a mere $47 of diesel fuel sounds like a bit too much fun to pass up. That's exactly the adventure the Adler family undertook this year, and while the $100k+ spent on the RV and waste vegetable oil conversion doesn't make the whole undertaking an exact steal, we've still got mad love for the project. With help from the crazies over at Frybrid, who specialize in diesel/vegetable oil engine conversions, Mr. MidLifeCrisis Adler was able to get his 21 ton, 40-foot luxury RV outfitted for sucking up waste vegetable oil from fast food joints, and converting that gunk into usable fuel on the fly as the Adler fam enjoyed the countryside. The whole trip, originally slotted for 3 weeks, ended up lasting 78 days and costing 6-year-old Julia her tooth fairy money to get through the final toll booth, but the story proves to be quite a bit more entertaining than Robin Williams' RV
, and the alterna-fuel experiment is a notable one.