Bed Covers and MPG

How's it going TacomaWorld!

So I've been in an argument about Bed covers helping MPG. It started when a friend mentioned their 4Runner gets better MPG than their Taco. His explanation was that the Taco gets drag from wind hitting the tailgate. My explanation is that the 4Runner has the Duel VVT-i which helps (I'm actually not sure if the Tacomas have this now too). My friend says if I get a bed cover my MPG would be higher like his (in the 20's, I'm averaging a little over 18). I've heard that the tailgate helps build a "vortex" of wind in the bed that helps lighten the truck or something like that. I've actually witnessed this "vortex" thing from seeing leaves flying around in the back in a circular motion. I didn't think a bed cover would make a difference.

Anybody have more knowledge that helps? Is my friend right about the wind drag? Are we both wrong?

Anybody have a bed cover and noticed an increase in MPG?

And can anybody confirm the Duel VVT-i helps the 4Runners or am I wrong about that?


Thanks for any info

 

Mythbusters did a thing on the tailgate open or closed for better MPG's, and there was no difference. The vortex doesn't make the truck "lighter", it just kinda shoots the air over the tailgate, so cover, tailgate down, etc... Makes no change.

 

I heard about the Mythbuster's episode that did it but I never saw it. That makes a lot more sense though that the vortex shoots air over. Thanks

 

My buddies were talking about it and It may not save your MPG but it will make it more aerodynamic. Even though the beds already have premade holes that allow the air to easily circulate, by covering your bed you do allow a better air flow giving you a a little extra "Oomff" in your ponies. LOL

 

I have read scientific material, which I cannot find the link now
and a toneau cover will help your MPG.
I am putting mine back on this weekend and should know within 2 weeks. I "expect"
.5 to .75 MPG improvement while driving 70MPH. Will update.
I have a 98-4Cyl Manual. A 6-cul auto should be less improvement.

 

I had my taco for about 3 months before I got my leer cap, back then I tracked my mileage with fuelly pretty closely. I saw no change at all, better or worse

 

It is a fine line. You are adding weight but making it more aerodynamic. IMHO I think/believe a reg tonneau cover helps but as you get into the hard fiberglass covers it is a wash or worse

 

It all depends.....

On my 96 tacoma, I saw a marginal (1-2mpg) increase with a bed cover (soft cover).

On my 2007, I have not seen any increase (soft cover).

Definitely not anything to brag about because its like slicing hairs.....

 

Looking forward to your update

I also thought about the weight of the cover and tried using it as an arguing point. In the end neither of us believed the other haha

 

I added a soft cover at about 15K miles, not for additional MPG but because I needed waterproof bed storage. I had been keeping a post break in MPG spreadsheet and had about 25 tanks on it when I installed the cover. After having it on for about another 25 tanks, the average difference in the MPG was .4 MPG improvement. This is across seasons with all types of driving both pre and post. 2007 doublecab prerunner

 

I had a double cab short bed and did not calculate any noticable difference between having an open bed and having a tonneau. I did notice my MPG's were better with a shell though by about 2 MPG consistantly.

 

I get .5-2mpg better with my 13 DC TRD sport with a 6 speed. The tonneau is a Lund genisis elite. Myth busters test results lowering the tailgate makes no difference in mpg hasn't been my experience owning trucks for 40yrs. My gas mileage savings is no myth! Hope this helps.

 

+2MPG with a shell is awesome!

 

I just added a shell and MPGs jumped from 17.3 to 18.7. Needless to say I'm pleased

 

Seems like the soft covers are the way to go for better MPG.

 

I would have thought for sure the shells would be the worst for MPG, considering the weight. Good for you though man, the extra mile per gallon makes a difference

 

My dclb saw no noticeable difference with my leer cap. Maybe weight offset aerodynamics?

Aulthough it does handle better in the snow with it

 

Since you're on the East Coast the added handling in snow is great. Plus you saw no noticeable difference so you didn't lose MPG either. Win Win