I've heard alot of conflicting stories about bedcovers helping gas mileage or not. Any share their experiances? I'm not going to bother spending my time to make one if it wont help out my gas mileage~

 

I've got a F250 and put a bed cover on it.It didn'tmake a differance except keeping crap out of the bed.A lot of places claim 10% increase in milage but I didn't see it .

 

might get a little MPG but not enough to ever pay for the cover.

 

How about change in MPG after installing a bed cap? Getting a cab-high cap this week on my F250 SD CC and just wondering if will do anything for the old range/tank of gas...

Edmo

 

It would seem to me that the closed tailgate would act just like the rear spoiler on a race car, except as it is standing straight up, and would be all drag with little downforce. Secondly, the blunt rear end of the truck would be dragging an area of lowpressure behind the truck down the road also creating drag. One could eliminate both by dropping the tail gate or installing one of those web belt tail gates. It seems that the cover would help with the first drag issue of the upright tail gate but still leave the low pressure area behind the truck. Maybe there is a wind tunnel engineer lurking out there who could give a more definitive answer.

 

No matter if you have a cover or not, there is still going ot be a low pressure area in the rear. The cover will make a 10% difference if you constantly drive on the highway at 80mph i bet haha. You will only really see a different if you're on the highway a lot, i mostly drive around town and around 35-40 mph so i didnt notice much of a MPG difference but having a cover is very nice. Hope my input helps.

 

Ok, here's the story from the laboratory point of view, for what it's worth:

One of my university engineering projects involved calculating aerodynamics of large objects, so we chose a pickup truck with various bed additions and stuck it in the wind tunnel. It was a Ford Ranger, funny, at the time I thought, "geesh, who would want to buy a Ford?!?" Anyway, long story short, the results in best to worst order:

1. Wedge-shaped hard cover, tailgate in normal position
2. Flat "tonneau" style cover, tailgate in normal position
3. Tailgate down
4. Tailgate up
5. Tailgate removed
6. Tailgate net

We did not test a "square" cover (cab height cover).

The tailgate net gave really bad numbers. Made a good brake. The covers gave 3 to 5 percent less drag than having the gate up. We never tested real world effects, but the covers should give at least a small mileage increase.

 

Real World Exp. . . Last fall a co-worker and myself who had many discussions on this subject decided to do a "real world" test. He always ran around with his tail gate down insisting on noticing increased MPG. I instisted that the results would #1 likily not be noticable & #2 be a hazard when backing up. (ever see all the tail gates with the nice semi circle dent in the top)

Any I drive 50 miles one way to the office and also travel to various jobsites throughout the week. Most of these 500 to 1000 miles per week are highway with an empty bed, and yes a heavy foot.

We decided I would use my 1998 F-150 Ext Cab, 5.4L, auto trans, 3.55 rear gear company truck for our "real world" test. We ran Five (5) tanks of gas for each configuration and threw out the best and worst average MPG tanks of the 5. Results follow:

1. Tailgate up (baseline) 16.52 MPG average
2. Tailgate down 16.57 MPG HONEST!
3. Hard Tanneu cover 16.98 MPG
4. Cab High Cap 17.12 MPG

Yes I was wrong and lost our bet! As cheap as I am I still miss that $20 too! Of course the increase in MPG was and still is in my mind totally irrelevant, It's just not enough to make it worth getting a cap for.

The real benifit to bed covers of any kind is that they provide modest security and protection from the weather for items stored in the bed of your truck. That combined with ?improved? style should be the real considerations in making this purchase decision.

By the way, I did get the last laugh on my buddy (though not in his face out of respect) his wife was backing his truck out of their driveway and bumped the neighbors mailbox with the lowered tailgate. Sure am glad he saved all that money on gas cuz now in addition to repairing the mailbox post, he gets to replace his tailgate

Petrol
XLT 5.4L

 

got a noticable differense out of my soft cover. the truck just dont act like it drags along on the interstate

 

Mine actually helped alot. Before, i was filling up about every week and a half, and after putting it on, didnt have to fill up but about once a month, less sometimes, with the same amount, if not more, of driving. Only problem is, that when it sits outside 24/7 in a spot where sunlight really hits the truck, the foam pads on the bottom of the rails melt to the bed rails of the truck. OOPS

 

I installed my cover too early to tell if it made any difference in mileage. The link below is interesting though... even if they did use a Dodge as the test truck.

http://mars.acnet.wnec.edu/~ehaffner/did.htm


Matt

2002, F250 SD, SC, 8' Bed, V10, 3.73 LS, Arizona Beige Clearcoat Metalic, ICI Stainless Step Bars, Truxedo Tonneau, Prodigy Brake Control

 

In the test with the truck, it said the test were performed on a water tuneel. Correct me if i am wrong but, this would mean that scale models were used not the real truck. Would the scale model effect the results any?

Chris

 

Read a little further. The various configurations are explained on that page, and have photos of the tests themselves. It was a full size truck subjected to water spray.

Very elegant study.

 

ok i'm wearing the dunce cap. i didn't click on the links.

Chris

 

[updated:LAST EDITED ON 19-Nov-02 AT 06:23 PM (EST)]As a side, why do all soft bed covers
turnout 2b cheap vinyl.

I guess what I need is a bedcover
made out of the same fabric (canvas?)
as convertible tops.
Any suggestions/help is appreciated.