Material for front air dam

[dwestmodesto]

Has anybody tried the heavy duty RV rockguard http://www.pacificrvparts.com/Produc...tselect&SID=73
It is 3/8" rubber reinforced with cord. It says it has stiffeners built in. It looks flexible, and is made to be mounted to the back of a RV...It might find its way mounted to the front of my Dodge Ram2500 Cummins diesel. It looks like if I buy the largest size, It would be enough material to make two flexible airdams for a large pickup. A guy on the CumminsForum just made an extended airdam, and reported 3-4mpg improvement. He wants to sell his though, for a high price. http://www.cumminsforum.com/forum/3r...-increase.html
Anybody else out there trying to get mileage out of Dodge Cummins? Best I have seen is 23mpg highway without my camper mounted.
Dave

Originally Posted by goodella@hartwick.edu

I went to the hardware store with a front air dam in mind, and after reading that people used flexible garden edging I found some, but it was only a few inches tall, and has a big loop on the top for a tube (I guess to hold shape? I certainly don't own a garden! ). Is that what people here have used? I would have to mount it with the fat end down, but it just seemed not tall enough in general.

The good news, is that my car has the perfect setup to add a dam! There's already a once inch tall one (no idea why), and I'm going to start taking that off. A simple set of right angle brackets and whatever material I find to make the dam and it will be done in no time!

Is there anything other than garden edging people have found?

Thanks

[Edit: I got a new username, GeekGuyAndy, since I am afraid this one will start getting spammed.]

[theholycow]

Do you drive enough for an investment like that to pay for itself? That question is, of course, assuming that its results are as you expect and you're doing it to save money.

A guy on a Cummins forum said he got better fuel economy from an aerodynamic improvement? Those guys usually say that they get the same MPG towing a camper or large boat as they do unhitched.

[dwestmodesto]

Originally Posted by theholycow

Do you drive enough for an investment like that to pay for itself? That question is, of course, assuming that its results are as you expect and you're doing it to save money.

A guy on a Cummins forum said he got better fuel economy from an aerodynamic improvement? Those guys usually say that they get the same MPG towing a camper or large boat as they do unhitched.

$100 at $3/gallon for diesel makes 33.3 gallons of fuel. If I can raise my mileage 3 mpg, it won't take too long to long to break even on the $100 investment. Aerodynamics and towing make a massive difference on my diesel truck. Traveling on highway with just a small load in bed, I average about 21mpg. With a cabover camper, (screws aerodynamics and adds 2000lbs) that drops to about 15mpg highway. Stopping and starting with extra weight makes an even bigger difference. On farm roads, every stop sign lowers my mileage. Lots of guys buy the diesels specifically because they get better mileage than the gasoline trucks.

[GasSavers_Pete]

I have used the fibre reinforced rubber (sold here as conveyer belting for transporting bulk materials like sand and gravel) before but I have no idea of the specs or designation apart from "Goodyear" who are the makers.

Works well enough.

Cheap , fairly flexible and looks like it is factory in some applications.
I used it as a temporary dust / stone deflector at the back of the car when living in the country all those years ago.

Pete.

[GasSavers_JoeBob]

I've thought about a front air dam, however, I have bottomed out more than once going into driveways, especially the one at my local Autozone, and the one when I leave my local Lowe's. What would work as an air dam, but be flexible enough (or sturdy enough) to take hits on pavement?

[theholycow]

The plastic that is used for the OEM air dam on my 2002 GMC Sierra would. It's kinda rubbery. Also, the air dams under GM vehicles that get their cooling from underneath, I think they're spring-hinged as well as being tough rubbery plastic.

[GasSavers_Pete]

Originally Posted by JoeBob

What would work as an air dam, but be flexible enough (or sturdy enough) to take hits on pavement?

Polyurethane or the stuff kitchen chopping boards are made from.
Can't recall the name of that just off hand. HDPE?

Tough , flexible and unlikely to crack or split around the attachment points.

Pete.

[magua]

how effective are air dams really? in years past i've never really considered doing much to improve my mpg besides driving habits... now i'm getting more interested. just curious how worthwhile making an air dam is and what the best materials would be.

a few years back i hit a wild boar with my old chevy pickup. it tore up my air dam and rather than replace it i just took it off. maybe that was a mistake...

[odiekokee]

chopping boards are either hdpe or uhmw plastic. I think the conveyor belting would be a good thing to try, may do it myself. Right now i have the 8" garden edging on mine. no particular noticeable benefit or detriment, but it's not doing all that much either. Does help some with heavy wind against my rollerskate.

[spotaneagle]

I just made an aero mode over my fog light ports out of a rubber made plastic bin, this is good material, as it is strong and sort of flexible in the right, and you can cut it with good scissors.

I went to wal-mart, home-depot ect looking for plastic and couldn't find any,, so I said to myself, not gonna spend $$ on this, and used that, I spent 8$ on clips from the auto part store, but they are tapered on the top and fit nice into drilled holes, ok so that's 29$ total on all of my mods.(20$ spacers)
caulk in aerodynamic fashion, and better than the aero mods on the new chevy cruze.. my inspiration for this mod(that I first did with tape) originally was the Bugatti Veyron aero setup

http://www.youtube.com/watch?v=jk1t6S737Cs