Sevir

Try again, this is a myth. having your tailgate up is actually better fuel economy then having it down. I saw it on mythbusters and I also did my own test. I drove up to memphis TN from Mobile Alabama (400 miles about 1 tank) I filled my tank to the filler neck and headed up to memphis with the tailgate up. when i got there i immediatly went to a fuel station and pumped 26.47 gallons into the tank. Just before i drove back down i went to the same fuel station and filled the tank to the filler neck and started heading back down. When i got to mobile i went to the same fuel station i started with and pumped 28.22 gallons into the tank. I got almost 2 gallons ( = 40 or so miles) extra with the tailgate up. I dont know if having a bed cover helps, but if you dont have one having the tailgate up is better for you.

Javahjoeo

I purchased my 03 Dodge Diesel,used, w/3044 mi, ( see my sig.) it had a bed cover, ( not hard top). I have to remove it to pull my trailers. I only makes sence that when you cover the bed, you help your MPG. I "KNOW" that my MPG go's up when I have the cover on. Soft cover works for me because I need to remove it from time to time. Javahjoeo from Kokomo

Deezle98

Yes but you have to remember that they (and you) tested with the tailgate down, not off. According to their airflow test the drag was produced by the air pushing down on the tailgate, so if the tailgate was off the air would have nothing to push against. Im not debating that leaving tailgate down hurts milage but I believe having it off may help.

bekim

Let me qualify my findings a little better. I keep track of mileage on every tank. Doing the same commute day in and day out year round. I drove around without the tonneau cover for 53,000 miles. I also drove around another 41,000 miles with the cover. the first 53,000 miles were bone stock 318cid. The next were with tonneau cover only, about 18,500. The rest were with K&N intake system, Edelbrock Shorty headers, and Flowmaster exhaust. Still, the best improvement I could get was the last few thousand with the engine bolt-ons(not even 1 mile per gallon)
The look of the tonneau cover was good enough for me to buy one again!
The sound and power improvement with the bolt-ons was worth every penny(30+Hp)!!
Cheers
Mike
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reidry

Here is a link to SEMA.org and their discussion of aftermarket covers and caps. They reference a study on "Improving Aerodynamic Characteristics of a Dodge Ram Pickup Truck".

Here is a link to TruckGagets.com where they reference a study by Ford, the University of Michigan and again the Dodge Ram Pickup Truck study.

Not sure if any of this would be considered credible evidence, but the vendors sure would like us to believe it.

Ryan

boostjunkie1

This has been tested time and time again. The only reason that he is seeing a gain in mpg is the fact that he bought the truck with little mileage on it. These Diesels will not reach optimum performance (mileage) until they get around 25-30k on them. I have had 2 Cummins and both 6 speed or Auto at around 30k the mileage stabled out to what it would get from then on with the same driving/fuel. ALWAYS hand calculate MPG, the overhead is good for long trips on highway. Put a trailer behind you and you will be off compared to the overhead guranteed.
Tonneau covers are a great investment if you buy a lockable, hard cover. Look great, and protect the bed and stored items. In no way do they help mileage-----------well let me retract that statment.
Short bed trucks= forget about it-----the air passing over the cab dosent have enough time to get drawn down to impact the tailgate.
Long Bed trucks--------only if at around 80 mph SUSTAINED will the covers help gain MPG---this has been found to average about .0836 mpg at the most. In extremely controlled studies.

fredbert

A couple of kids from Western New England College, AKA "Winky U"? We ain't exactly talking MIT here! If there is really something to it, SEMA with all its resources would have come up with or sponsored something much more credible. I am in the market for a tonneau cover, but I'm not counting on any fuel savings.

ducktape

OT, does anyone know what wheels are on the red Ram?

Jme

Thats what I have and I love the **** thing. Best $900 I have spent lately. Love the locking and the seal it provides. And on the Ram it fits flush on the sides, unlike the F250 and sorts with the .5 " overhang.

RamWheelsBy4

I put an Undercover lid on this morning. Had SnugLid XL on the previous truck and had one of the new Snuglid XLs put on this one when I first bought it. The new design Snuglid center single lock with spring load was nice, but they could not keep it, actually two of them from leaking around the lock. Too much beating with heavy duty 4x4. Have not had on one for over year now and really miss being able to load up my road stuff and just leave it in the back. Don't really care about any mileage improvement, but will take any there is.

The Undercover certainly is not as purdy as the Snuglid was, but seems more functional. Opens easy, opens higher, seems well sealed, I can take it off by myself in 5 minutes, cost 40% less and has a very bright set of battery powered LED lights.

A couple of pics, not very good day to be taking pics, drizzle rain.

redspider

how much $$$ are these undercovers

WACTD

...which is a bit of a discount from MSRP, I believe. I did my own installation which took less than an hour, and that's with me being really picky about alignment and testing.

I spoke to the owner and the national sales manager of the company before buying, and was impressed with their attitude and support. The local dealer was great, too.

It looks and fits like something Dodge themselves designed specifically for my truck. I also like the design of the locks and the LED light on the underside, which does a nice job of illuminating the bed at night. Even my hard-core Chevy and Ford friends have been complimenting me on how great it looks.

The whole product and experience have been excellent and I strongly recommend it if you're looking for a tonneau.

RamWheelsBy4

Cheapest I found local was $645. But pain to go get from them. Wound up paying $699 installed at the Master Hitch down the street from work. Worth it to me for convience and time savings. They made a special trip to the local wholesaler so it would be there when I wanted installed.

goose2

Does anybody know if they make the undercover for the long bed?

bekim

Excellent evidence Ryan! Those studies will surely sell more hard bedcovers!!
Nonetheless, the only evidence that mattered to me was how it affected my mileage on my truck. I loved my tonneau cover for more reasons than the expected mileage gain(security, kept everything dry). Just an observation, I almost never got 16 mpg anywhere to start with
Cheers
Mike
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