Originally Posted by socalborn

You know for a fact huh? Well either you drive on another planet or you don't know what the word fact means. Tailgate up creates an air bubble that results in trucks being more aerodynamic resulting in better gas mileage. Sorry to disprove your "fact". The best way to improve gas mileage is with a really good tuner. Get someone in the truck while you diver and if they know what they're doing you'll feel a huge difference and increase MPG. Don't listen to any advice from anyone that says a tailgate down is best. Good luck.my 2006 5.3 HO gets about 15 on the streets and probably around 18 or 19 hwy

Originally Posted by Nick99Chevy

Did you notice that this thread is 13 years old?