Gas milage went up 1 mpg

I bought the bed cover from the Toyota dealer and he said your gas mileage will go up about 1 mpg. I didn't pay much attention to that , because I didn't believe it. I got 16.8 on the first tank now I'm getting 17.8 driving the same way I always drive in the city. Could that be true or does it get better mileage after the first tank anyway?

 

Drive it 10 tanks worth and then draw a conclusion. Sounds like you only have 2 (or very few) data points.

 

The cover fills the void so no air hits the tail gate. Without it, most of the air goes over the cab and tailgate, but some goes into the bed creating drag.

 

Yeah you got less drag with the cover...the dealer is right

 

Wasnt this myth busted?

 

I thought they did it on myth busters. Ran with tail gate up and down or something like that. Also did test with ac on and off.

 

Yeah they said the bed makes an swirling air bubble. And the air flows over the pocket of swirling air. But who knows

 

I don’t know. I have a bed cover and was hoping for a slight increase. But, I don’t notice a difference with it open or closed. I’m not a believer. Too many other variables.

 

Surely a member here has access to a wind tunnel. I refuse to believe this community cannot deliver! It's solved crimes dammit!

 

I remember an old cartalk episode where a lady said she gets better mpg after an oil change. . . Eventually after several oil changes they figured out the shop put air in her tires when they changed the oil. . .

 

Had the cover on my 17’, it did in fact give me an extra mpg.

 

I believe carrying the weight of the cover kills any mpg's gained by aerodynamics. Someone else mentioned this before

 

The weight is negligable, thats like saying having a passenger will ruin your mpgs.

 

Mythbusters was more entertainment than good science. Only you can determine your mileage and how mods affect it. If you care you'll probably do better than if you don't. Also, a 2.7l might show more gains than a 3.4l just because it takes more foot to offset the drag.

 

The difference is pretty negligible. The slight increase in aerodynamics is offset by the slight increase in weight.

I didn't notice any difference with my Bakflip cover and it doesn't weigh a whole lot.

 

I drive 100 miles each way to work, from sea level to 1000’ elevation and back down to flat lands. 36k miles of commute. All bone stock TRD Sport 4x4. Light footed with varying speeds of 70-80mph. This is my second best MPG, best was 23.2 MPG but didn’t take a pic.

 

If it is true, I need about 4 or 5 bed covers to get the same mileage as most of you guys

 

On a vehicle 10 years ago. Designs change and I wouldn't be surprised if they designed the aerodynamics on our trucks to take advantage of a bed cover to help with emissions and milage requiments.

 

Exactly.

Hey, I enjoyed the show and liked those guys.
But man, they were in over their heads when they tried to explain physics.
And they were hopeless when it came to setting up objective tests.

Even worse, they often did insufficient background research.
You see, empirical reality trumps theory every single time when the two conflict.

I can think of two examples just off the top of my head:

So, they concluded a shark can't ram and sink a boat.
Sorry guys, there's at least one documented case.
In that one, a Great White shark rammed and sank a dory.
A dory is a fishing boat, typically over 20 feet long.
(Dories were used extensively for commercial cod fishing many years ago.)
If they'd bothered looking it up, they would have known.
But their "test" was ridiculous anyway.

In another, they said it's impossible to electrocute oneself by urinating on a third rail.
They concluded that a stream of urine would break up into droplets and would be unable to carry an electric current.
This was based on the feed flow of precisely ONE bathroom visit by Adam.
Any man can attest to the fact that the flow can vary.
Anyway, they were apparently unaware of the electrocution death of one Joseph Patrick O'Malley.
Who was in fact a real person.

As to the tonneau thing and MPG, I dunno.

 

I can give some real world experience to this one. I live in NC. For the last 25 year's i have driven home to covington LA twice a year to visit family. 1100 miles one way. 28 hours round trip drive time. Several different vehicles, cars and trucks. Trailgate down, tonneau on and off the same truck. It really doesn't matter. I could tell you within 20 miles of empty every exit we needed to stop at.

As far as mpg on the new truck... That's just engine and transmission breaking in. Just bought mine too. 16.8 on first tank. 18.4 on second. 19.5 currently on third. Driving same road every day.