tschaid said: "Mythbusters answered this question. The answer was: Without the bed cover fuel economy was better than with the bed cover."


I do beleive it was the tailgate they were testing. Search mythbusters. Trucks today are designed with the best MPG with the tailgate in its closed/up position. With it up, it causes a rolling low pressure bubble in the bed of the truck. This rolling low pressure bubble, keeps the high pressure air from hitting the trucks bed and tailgate, creating less resistance on the truck. With the tailgate down, much higher wind resistance is created on the trucks bed because the tailgate is not in position to create the rolling low presure bubble...

Now with the Retrax bed cover that I have my truck. I beleive it is better than the tailgate down, but not as good as with the tailgate up... Smaller bubble, little more wind resistance, that extra wind is quicker to dispate the resistance due to no bed side walls to bring into the equation... Just my thoughts...

 

I actually need to retract this statement. My wife told me that she was seeing 16.5 in the truck. I get in it and drive and see no more than 15.

So, nevermind.....I still lost a little mpg with the tune.

 

I'm getting 18-19 HWY with A/C on on Mikes 93 tune

 

Yep, my new TP tunes are giving me better mpg; I’m knocking down 17 now, all local driving

 

My 2005 Screw 5.4 w/ 3:73 basically stock will not budge from 11.8 to 12.1 MPG's. Hwy, City, even towing by 22' boat it doesn't matter. I get around 12MPG do matter how I drive it or what I haul.

What Mod's should I do to improve by gas mileage...and hey...if I gain some horses too that just sweetens the deal.

 

 

I did 17.29mpg in my truck (11k on it) on my last trip to and from Maine. That was in the boost when ever "necessary" . I think it has a lot to do with the Troyer tune.

 

Wow! is that 87 or 93 tune :lol

 

Playing hard with my truck on the street and hiway I still get 12 MPG. Hitting WOT, quick starts, ect... Going easy on the hiway with OD on, AC on at 70 MPH, with the cruise control on, I get a solid 18.5/19 MPG. I am sure SCT MT tuned tuner is a major contribruter to that MPG#. I run the 93 performance tune exclusively on my rig. My hard bed cover might give me 1 or so help... I am still deciding on my exhaust...

 

On the hwy, cruise on at 68-70, running empty, 21mpg using 87octane. Truck is stock... Not for long

 

I usually get 13/14.5 town/highway. Highway should be better, but hills around here kill it. Did get 16.5 on a trip to Corpus a while back. This is stock, but I hope to alleviate that soon with some money sent to Mr. Troyer.

 

The mythbuster question was tailgate up or down. The results were obvious, tailgate down acted as a big spoiler increasing drag. Tailgate up created an air bubble in the bed which forced air to go over the bed. I have no proof of mpg gains from a tonneau but I am pretty sure it would reduce drag.