Help me get better then 6 mpg please.

[GasSavers_mikemoss]

I recently started a new job that involves us driving all over the country. The catch is that the truck and trailer that the company gave us were never meant to be used together.

We have a 2005 Ford f150 lariat like this

http://www.classyauto.com/image342622.img

and a trailer roughly like this

http://www.mtairygolf.com/14%20foot%...h%20lights.JPG

Our trailer might be a little longer but basically like that. Im not sure how much it weighs but I would guess somewhere in the 7000lb range. The truck now cant pull it in overdrive and we are averaging between 6 and 8 mpg depending on the road.

What are the best areo mods we could do to the 2 things in order to increase economy? We cant do much to the truck now bc it is still under warrantee.


Thanks for any help.

Michael

[theholycow]

You can boattail the trailer, or just edge it (if that's the way to describe it). My sig meta thread has a link to a PDF at NASA's website where they tested aerodynamic mods for big tractor trailer boxes, and found that an edge hanging off the back helps.

Edit: Here's the links:
http://www.nasa.gov/centers/dryden/p...ain_H-2283.pdf
http://permanent.access.gpo.gov/webs...00-01-2209.pdf
http://www.greencarcongress.com/2005...at_tail_d.html

[GasSavers_mikemoss]

Cool thanks. Ill have to read that soon. Dont think we can boattail bc there are doors on the back. But a hangover thing on the back could be possible.

I have read that vortex generators may or may not help mileage but will they always help stability? And would they be effective on the trailer since it is just square at the back? This trailer catches the wind like a sail and the truck doesnt weigh enough to keep it strait, same happens when trucks pass.

Thanks

[JanGeo]

Sounds like you need to put a cap on the back of the truck to help the air flow and transfer some weight to the truck bed as well. The air tabs probably would help the trailer since that is exactally what they are designed to do.

[GasSavers_mikemoss]

The bed has a tauno cover. The things we would do wouldnt be funded by the company, most likely, so for now I would like simple cheap ideas. I have thought about a partial grill block but I think we need to get all the heat out of the engine/tranny as possible.

How much would putting wheel skirts on the trailor help?

[Jay2TheRescue]

I think a Kammbak (sp?) on the trailer will be the best aero mod to do.

[theholycow]

Whatever you do, make absolutely sure the transmission can get as much cooling as possible. There's nothing tougher on an automatic transmission than towing (well, maybe snowplowing), and no part more vulnerable to towing damage than the transmission. Increased cooling and frequent transmission fluid changes are what makes an automatic transmission survive difficulty.

[theclencher]

I doubt if a grille block is a good idea when pulling. The minute aero improvement is less important than preventing overheating.

Airtabs are also a minute improvement at best.

Skirts are a minute improvement too. But if you have some free coroplast or other appropriate materials lying around and can make some that don't look clownish, might as well. I wouldn't do the truck though.

The cap is by far the best idea, along with xfering some weight to the truck. It's "tonneau" cover BTW.

Second best might be partial kamm back on the trailer, a.k.a. "Clarkson device" as in holycow's last link. They didn't invent that though, so I'd hesitate to name it after them.

A deeper airdam might help some.

It's going to have awful aero no matter what you do unless you get radical and you can't really do that on someone else's rig. So then what? Keep it under 55 mph. I've found that when doing heavy pulling with my F150, 50-54 mph seems to be optimal. It's a sweet spot, juuuuuust fast enough to get overdrive (if there's no uphill or headwind) and juuuuuust slow enough to keep it from downshifting for every little thing.

6 mpg?!? I can't freekin' believe that. My F150 is a '94 with the 5.0, and even when doing the aforementioned heavy pulling it gets about 12 mpg.

[DRW]

Don't forget the basics like tire pressure. I'm not recomending raising the tire pressure too high, maybe just 5 psi above recomended pressure. I'd also check the wheelbearings to make sure they rotate smoothly.

Don't forget your driving habits. Keep the throttle steady, use cruise control when possible. Try to avoid flooring the throttle and avoid hard braking. If you look ahead and anticipate changing traffic conditions you should be able to get on and off the gas and brake sooner, which saves gas.

[GasSavers_bobski]

Originally Posted by mikemoss

How much would putting wheel skirts on the trailor help?

Lipstick on a pig. From the pics, it looks like half of that trailer is sticking up in the wind, aerodynamic brick style. You need to smooth out the front of the trailer or bridge the gap between the truck cab and front of the trailer with a cap as JanGeo suggested.