aeromods for trailer?
 

Haven't found much but... Are their any who mod their trailers? I am almost done making my side by side trailer and was curious if others have done anything with success? I.E. side skirts, some sort of angled material from the flat bed pointed up say at 45 degrees or something?

Or is it not really worth it?

I would be towing a 2017 teryx4 with approx. 80in height and a full windshield on a 16ft total length tandem axel trailer. its an old demod RV that I've just scored, added bracing, cut some length off and added fenders. Currently gonna sand/prep metal for paint and add the decking.

I couldn't find much so thought id ask the experts.

Most trailers are pretty bad for aero, so aero treatments would most likely help. Small things like smooth wheels would likely have a small benefit on, say, a 30ft trailer, but in a smaller trailer molding the front, sides, and rear similar to the aero template would likely show some benefit.

Obviously any ROI would depend on how often you use the trailer.

The trailer pretty much drafts the tow vehicle like how Nextel cup car drivers draft each other.
So as long as your trailer doesn't stick out the sides or above there isn't a lot you can do.

If it's a big ass camper you want to pull search tractor trailer and RV aero mods.
A hump on the roof, side skirts, boat tail can help a lot.

Ok cool that's actually helpful information. I was thinking of experimenting with inserting a braced piece of plywood on the front and angle it up/back towards the cargo kind of like the air ramps that reduce the whistle on roof racks/baskets. But I gotta measure I have a feeling the side by side on the trailer is going to be a hair taller than my truck. I could fab some skirts on the sides on a hinge that way I can fold them up for rocky /knarly roads and use some thin metal and like the hardplastic signs etc.

I will goof around see what I can get material wise for free/ cheap.

appreciate the info. I was kind of thinking like the red lines I added to the basic image of a trailer etc. Mine would not have the side railing etc.

I'd say the biggest improvement is to cover the top. That open cavity creates huge drag, which I've noticed largely goes away when towing nearly a full height load.

So we're talking about a flatbed trailer carrying UTVs? Secured with straps over the tires and recessed holdfasts?

I would ditch the angled plate for streamlining the UTVs themselves, maybe with a tarpaulin. The trailer is a flat plate, give the edge a generous radius. Pontoon fenders.

https://ecomodder.com/forum/member-f...llmystery1.jpg

trailer mods
 

BamZipPow's T-100 kit,and integral one-wheel aero trailer has pushed his mpg,from 19 HWY,to over 30 HWY if I remember correctly.He's got his own thread.
I failed to properly tighten the lugnuts on my 2-wheeler and lost a wheel when testing,and I've never repaired the damage an re-tested.The trailer,so far, doesn't reduce the mpg at all.
The first trailer dropped the mpg of my CRX from 52,to an average 50 mpg, while running 'empty',then with a quarter-ton of batteries,from Texas out to California and back.
I'll be simulating a 1-wheeler when I go back to the wind tunnel in a year.I'm shooting for Cd 0.14.

Before finishing this thread, take a picture of the rig while hitched. Preferably while loaded. That is sometimes enough to spark things.

The easiest mod for your scenario is to keep it at a max speed of 55, where aero doesn't make much of an impact. Trailer tires are usually only rated for 55 anyway, unless we're talking .5" rim size truck tires.

Other than that make sure your bearings are in good shape with plenty of grease, and keep your tires aired up all the way.

Most trailer tire specials that I've seen are rated at 65 mph.

Trailer is not finished yet but did get all the cross braces welded, did some test fitting for tie down attachments on frame, adjusted/welded fenders on, last night sanded and wire wheeled/ repaired some older bad factory welds. The tires are used d rated truck tires 225/75r15 rated for more than 70mph. I thought about getting brand new st trailer tires but I was trying to keep cost down and figured these are about 5 years old with no cracking and rated above 2.5k each at max psi but the side by side weighs 1725lb stock maybe 100lb more with spare tire, jack, 2 gallon fuel, and few tools. The trailer has tandem 5 lug axels. figured im under 3700lb trailer/cargo combined.

truck/trailer speed limit here is 65mph but most trucks go almost 70. If I try anything under 65 I'll have more people on my tail than flies on fresh cow poo. We have a lot of single lane highways where im at in North Idaho and not many pull outs except for run a way trucks on hills and truck stops but I feel good at 67mph. Keeps my rpms lower and people off my tail most of the time lol.

The truck is a 1999 f250 auto, 7.3 diesel, supercab shortbed 4x4 with a leveling kit and 285/75r16 tires with a aftermarket trubo compressor wheel, larger transmission cooler, straight pipe 3.5in exhaust, and a bed cover (easily 1-1.5mpg boost on road trips with that thing and no trailer). I have whats called a php hydra chip that changes the ecm settings. I have a 25hp heavy tow tune that works amazing when im towing the 5th wheel or small equipment. Really helps keep the truck in the powerband but doesn't do anything for fuel economy so truck is in stock mode 80% of the time.

I guess it may be a while but when the trailer is finished enough to at least put the side by side on i'll snag a picture and post the height, length of truck, trailer, trailer with side by side and stuff.

really appreciate the good info. It may not be worth adding skirts or anything to the trailer but ive got plenty of scrap steel/wood so i'll try lol

Technically those "Truck" speed limits don't apply to you, even a F250 pulling a large trailer is still a "light duty" truck. That said, I'm just across the boarder in north western Montana and will drive 55 all day if I want. People pass, I use pull outs. If I go much faster I'm going to end up on somebody else's back bumper. Then what? Have to pass them?
55 saves a ton of gas pulling a giant sail of a camper we have, it saved a ton of diesel when we used a Cummins. I'm also seldom in a hurry to get anywhere towing, it's called a vacation, and I want every minute to be relaxed.

67 on those mountain twisties sounds bad enough, let alone adding 5k worth of trailer behind. If your tires are rated for the speed they'll handle it, but I'd still slow down if I were you.

Aside from the aero help, that diesel will thank you big time if you keep the RPMs down a bit.

Edit to add: the "truck" speed limits only apply to commercial vehicles, a 3/4 or even one ton pickup is not a truck, no matter how auto companies like to advertise and sound tough.

I think you are right. I spent 10yrs through the military in CA and their truck speed limits apply to anyone with a added tow axel so I got used to that. There are very few roads in my area with a less than 65mph speed limit so im not gonna be that guy and constantly have to pull over to only get 2ish mpg more max with my truck. I do slow down for hills, take it slow on corners when necessary etc. Ive been towing equipment and trailers up to 48ft for good amount of time so I feel my driving is pretty conservative esp when loaded.

agree with the truck speed limit. Old habit from a bad state I spent a good amount of time in. I usually do go over 65 loaded anywhere just because of the added fuel consumption but 65 in the areas I drive seem to be the right blend of keeping people off my tail, keeping good distance from those ahead of me, sometimes I can even time traffic lights in congested areas but most of the time they fly around/ then in front of me so I just stay back and let them fight for the seconds saved lol.

Im gonna do some more work on the trailer tonight. May even be able to load the side by side on it to take some measurments. Probably next week the unit will be 100% though. Appreciate the info/thoughts. hoping to post a pic for your input soon.

Understand trying to "go with the flow". I do it too, both above and below ideal speeds. In Washington, the truck speed limit and the maximum speed is 60 for a huge part of the highway system from Olympia to past Everett, so it is pretty easy to take it easy :)
Get out toward Idaho on I-90 and it gets just like you say, big distances and people in a big hurry. I find a trucker with a light load and cruise control, and shadow him at a safe distance.

If those tires are five years old, time for new.

Tires that sit, dry rot. Heat from use is NEEDED to keep them in shape. The expectation is 3-5 years tops. Mileage not a trailer tire life consideration.

As to rig aero, the truck bed needs a cover. A thin piece of plywood extending from tailgate to 1/2 the distance to the cab.

As to MPG, it’s about steady-state. Below the flow of commercial traffic. One uses mirrors to manage their getting around your rig ASAP (slowing to accomplish this when they have less than a 5-mph variance). It’s a different set of habits.

The “goal” is maximum distance from all other vehicles throughout the day while still on cruise control. No lane changes (which means sub-65 travel speed).

A cruise control set of from 62-64/mph is as high as it gets. Then, monitoring traffic. With a jam of vehicles up ahead moving more slowly than this, one backs off in speed until it clears. It will. Always does.

Same with any passing. Done when alone. Only.

The relationship between Average MPH and Average MPG is the fundamental. Use engine hours against the day’s trip length for the former.

It’s a rude awakening for those who believe a speed like the above is too slow. As a faster speed that causes one to have to pass more doesn’t result in a faster trip time, per se. The few extra minutes “saved” means MPG gets a broken jaw.

Traffic volume (road design plus other conditions) dictates travel time. Not set speed.

A few mph extra can show NO BENEFIT, only deficit. I do this all day, every day.

In short, if there’s ever a time you’re within a football fields length of someone else, you need remedial instruction. (Heard the phrase, “cant fix stupid?” That’s the guy surrounded by other vehicles).

Safety trumps MPG, but, happily, they track each other most all the way.

Along with engine hours & odo reading at day’s beginning on a note card, also set categories for braking and acceleration events. Mark each one. If you’ve slowed to get someone around you faster AND can use a downslope to regain set speed, that doesn’t count against you.

The “ideal” trip has only one each of those events. Absolute zero idle time. The trip is from when parked from overnight, until being parked for the next night. All miles & time. Not highway only.

Planned stops only. And then, only after the original first two hours at highway speed (as this is the initial warmup and lessens re-start penalty). Make the stops at locations in the same direction of travel, and with fewest number PLUS degree of steering inputs. Etc. (These details matter greatly).

On the vehicle CONFIRM perfect alignment (Ford always a problem), trailer axle alignment, and that trailer brakes & bearings are properly adjusted. Trailer tire pressure should be to sidewall maximum. Truck tires are from a CAT SCALE weigh ticket and consultation of the Load & Pressure Table of that tire ratings category. (Inside vehicle manufacturer range). Not higher or lower as that worsens handling & braking.

One is also looking for caliper drag on the tow vehicle. And, with a turbodiesel CONFIRM no CAC leaks.

Seat posture is that ZERO reach is needed to the top of the steering wheel. Arms not at full extension. Mirrors adjusted accordingly. Driver fatigue is the thing. Everyone is affected. A bad seat cushion, as example, needs remedy. Alertness throughout the day is what preserves those tenths of a mpg.

Any aero with the trailers contents is worthwhile. But, first, CONFIRM that the trailer tongue weight is more than 10% of the trailers total weight.

At the CAT SCALE, do two passes after topping fuel tank and keeping all passengers aboard:

1). Rig as hitched.
2). Truck only.

At home prior to this, find a copy of the trailer tongue bathroom scale weighing method. Numerous sources. Find the empty and loaded values. Use a carpenters level on trailer to have it dead level when weighing.

To hitch the trailer one needs it as close to level as possible. A half-bubble out is almost too far. MASTERLOCK and some others used to sell an infinitely adjustable hitch that makes trailer leveling easy for under 5k of load. I bought mine at U-Haul. It’s an Acme Screw. One uses a box wrench to raise or lower.

MPG is a question of details. If you truly want it, then one has to chase them. An alignment good enough to get down the road ISN'T the same as ideal, for example.

Just as driving more slowly isn’t enough. It’s the totality of every input the truck receives through the day. Less is more.

As an example I’ve hooked up U-Hauls largest enclosed trailer and with a combined weight in excess of 13k still seen above 18-mpg towing on two separate trips of 350-miles. On a the truck below in signature, where, with almost a quarter-million miles is just finishing its second set of tires and has had one brake job. 50/50 Town & Country miles, it was spec’d with FE in mind.

MPG is a GREAT way to chase down details. See contributor Big Dave’s many Ford posts here, and see his Fuel Economy subforum on one of the Ford enthusiast sites.

One has to have a plan. Records. Baseline numbers.

Slowmover, your post should be on the bulletin boards of all commercial freight haulers who give-a-fig about economy and safety!

Doing it for a living lends focus. I’d imagine you'd have written the same with a shared background. Industry literature, training, and shared observations are the other part (talking shop). One can “test” almost any proposition on a daily basis. Driving is always of interest.

Aero is fun because it’s flat cool. Measuring it is the problem when mechanical condition or operator error cloud the picture.

I’ve noted before that I’d bet money on the sensitivity at the wheel of both BamZipPow or Aerohead (not to exclude anyone) as the depth of aero modifications highlights ANY other problem.

The rest of us are fatigued by wind noise and ennui. Takes a trip of substantial miles to get use-able numbers. Those two rigs (and any similar) are such that in 25-miles or less they have distinguished between mechanical & aerodynamic as to needed changes. Rome wasn’t built in a day.

Race cars.

For the rest of us — and especially those of us with used vehicles — what’s necessary is of a higher standard than most cars with good owners receive.

In the end, MPG (as with tire & brake life) is an indicator of longevity. Reliability. Putting safety first actually makes a longer day easier. Less effort expended. Thus the same end is served.

The best trip is one that is forgotten before one falls asleep. The scenery or other pleasant sensations needn’t be tied to a particular route over a particular day, after all.

The willingness to use records henceforth, and occasionally test, is what creates the improved annual average mpg (expressed in cents-per-Mile). Repairs, maintenance and driver habits are at issue. Emotions about money & self.

“Success” is the percentage reduction.

Now, will that be in reduction of total annual miles? (Greatest effect, and easiest to achieve). Or, in reduction of fuel burn per mile (maybe greater satisfaction, but harder both to quantify and to achieve).

As to a vacation, it’s been about ten years since I posted it, but it’s possible to underwrite nearly all or most vacation travel by diligence the rest of the year.

Anyone up for 5,000-miles of free fuel towing a travel trailer on vacation?

I was aware of — but hadn’t thought through — the discrepancy between highway & city mpg until Diesel Dave made it a challenge: close that gap!

So, we’re all just sitting around having a cold one, MG.

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slight update. I have 5 Carlisle 225/75r15s arriving tonight. Going to check, clean, re grease wheel bearings soon. Im staining the trailer deck material today after work and doing some more paint prep work.

I run with an adjustable hitch and try to get the trailer level. we also welded up the anchor points on the trailer so that the side by side sits where it needs to for tongue weight/balance etc. Im not totally ocd about mpg as sometimes I don't feel like going 10-15mpg under the speed limit even with no one around but I feel I drive safely and much safer than many of the folks around me. I only let the truck idle at a minimum for the turbo to cool and use the block heater/full synthetic oil for winters (made a huge improvement by the way) I was burning way to much of the rotella t6 5w-40 so Im trying the newer t6 15w-40 in full synthetic this winter. I burned about 1.5quarts in 5k with conventional 15w-40 but that nearly tripled on the 5w-40.

truck has zero external leaks and I have resealed the fuel bowl/filter housing and fuel lines, replaced seaping high pressure oil pump lines, all new hoses for just about everything. Im more ocd about maintenance and its paid off over the years. many 20+yr old vehicles I have run just great just don't have all the touch screen stuff.

I check air pressure every couple of months but I do a walk around and my wife still pokes fun of me but I've caught low tires and leaks that way many times.

Appreciate all the great info and again making progress so hoping to post a pic with measurements.

my towing mpg seems pretty consistent. I use diesel kleen in the winter and that actually helped a solid 1mpg with winter cut blend.

me towing around 8k with the equipment trailer around 14mpg avg, city/highway.

me towing around 12-15k 8-12mpg. big 5th wheels drag a lot and lumber just is heavy for a single rear wheel 7.3l diesel with an auto.

me towing under 4k honestly 16-17+ mpg easy on highway and around 14-16 combined.

I run the tonneau cover when im empty and it paid it self off with ONE ROAD TRIP LOL. couldn't believe all the stuff I learned in a few days here lol.

Not doing that bad, you're just below my "retired"18 mpg average in city with a 6 speed driving like an old man with a hat.

Check your calipers for drag after release, they're famous for that, my rr is showing signs.

That funny you mentioned it. I did re do my brakes in 2016 when I bought the truck. needed rotors and pads very badly and I cleaned/greased the caliper slide pins. I do check brakes every 5k when I change the oil/rotate the tires. I haven't seen above 19mpg in a while though. I got 19.5 with stock tires and no front leveling kit. but the tonneau cover helped more than I ever thought.


Does anyone have any data on those roof mounted wind deflectors? see them on big rigs but rarely on trucks pulling 5th wheels. I could fabricate one pretty easily and anyone can ask my wife I don't give a rats butt about what others think my truck looks like lol. shes nearly pristine for 20 yrs old.

I was thinking the wind deflector on my roof because the side my side may sit 1.5 higher on even my new trailer etc.

I didn't know how valid the picture attachment really was etc.

I'm pretty sure (BamZipPow or Aerohead will likely chime in if I'm wrong) that the airflow leaving the trailer is just as, if not more, important than the airflow hitting the front of the trailer. A slanted front will help, but a properly angled rear will likely help more.

There's a joke in there somewhere. :)

The tow vehicle deflector likely doesn't apply to your situation. I'm still waiting to see what this looks like. If it's a UTV on a flatbed trailer, the best bet would be pontoon fenders on the trailer and a boat tail on the UTV. Maybe a tarp over the nose of the UTV to smoothen it.

These pickups are known for being heavily biased to the undersized front brakes. 2 decent brake applications while towing can warp the rotors

valid
 

The original source included the drag coefficients for each configuration.I have it at PhotoBucket,but can no longer access any of it.
As to the deflectors,they need to be tuned,and do not lend themselves to just shooting from the hip.

I speed up before the hill upwards 90 miles an hour by the time i crest the hill i'm doing 60mph while keeping in 4th gear in the MPG band( accelerating up hill uses more gas then accelerating down hill or flat)


this will not work for trailer since most of the time the load is unstable over 70mph

Trailer tongue weight (measured; bathroom scale method) MUST be 10% or greater. Stability is dependent.

62-64/mph is more than fast enough. Keeps one out of the left lane. The new challenge is to manage overtaking traffic that they spend the least amount of time alongside.

State law prescribes weight limit for non-braked trailers. Must know weight. Brake actuation must be verified, and the controller set to engage HARDER than the tow vehicle. (TEKONSHA P3 controller minimum acceptable).

The test is that the combined Rig stops FASTER than the tow vehicle while solo.

Find the brake controller setting that does this with the hardest FULL stop AND least amount of trailer tire flat-spotting. (Test again on gravel or dirt).

Find the roads you can do these. It’s not an option. It’s basic. Same with the tongue weight percentage. BOTH need to be “working” to ensure trailer stability.

The contact patch of the trucks rear tires is the emergency allowance. Thus they CANNOT be overinflated. Use a CAT SCALE to get weights with and without trailer, max fuel as you arrive, and with all passengers aboard both times. Consult the Load & Pressure Table for that tire rating and NAIL it down.

A pickup is one lousy tow vehicle. High center of gravity and crippled steering & handling. It’ll roll where a car would spin. MUST reduce hazard. Tongue weight, brake actuation, and tire pressure are basic. (Trailer tires set to maximum).

Knowing ALL weights is a baseline record. Ideally the DRIVE Axle is heavier than the Steer Axle by 10% or greater when Towing. BEFORE one is hitched.

The weight in the truck bed must:

1). Be either atop or Forward of the Drive Axle; and,
2). All gear MUST be secured that in the event of a rollover that none of it comes out of the bed.

Yes, it’s all part of FE. Reduced steering corrections (input PLUS degree thereof) is so serious that both Cummins and Kenworth cite it in their literature.

Driver fatigue affects us all. Please DONT tell yourself you’re better than others at this. First, I’m better yet. So what? The RANGE of skill between all is so small as to be irrelevant. Second, what matters are those moments of inattention to which we are all prone. (Why steady-state on cruise control BELOW commercial traffic is a winner as fatigue takes its toll. No one is exempt). The later in the trip, the greater likelihood of a problem.

TRAILER AERO matters most with ability to handle cross-winds. The lower the profile, the better. Unequal braking action has aero consequences, as does bad trailer axle alignment. (First clue is shot leaf spring bushings; check them).

The gap between the pickup and the trailer is the source of most “bad” aero penalties. But hardest to fix. A deflector MAY help but is as likely to hurt (as Phil noted above).

Ford I-Beam front axle is your aero concern. Zero steering slop ATOP perfect alignment. My 1T has IFS with rack & pinion steering. Which of our trucks will require fewer inputs, brand-new? Which will EASILY surpass the THREE SECOND RULE of releasing the steering wheel and the truck DOESNT head for the ditch?

We don’t want the trailer to wander. At all. We want it “locked” to the tow vehicle. (I can follow you and video the wander. Chances are it will spend the least amount of time in alignment).

As the FORD steering gear type and front end slop baked-in by design gives TERRIBLE feel for what the trailer is doing, it will be too late by the time it’s felt.

Both vehicles can use new Shock absorbers (past 60k on pickup; get BILSTEIN air KONI) and the LIPPERT kit for the trailer. Otherwise, the tires must do two jobs, and this is what will get it sideways. Crow-hop. Shocks are insurance to keeping the tow vehicle tire contact patch undisturbed .

Loss-of-control can come with road surface camber changes, tripping hazards, and slick surfaces. We want EACH tire to maximize grip. Won’t happen with dead or non-existent shocks.

And these corrections makes a long day at the wheel easier. Least amount of I put to maintain headway. Which in turn makes traffic management less onerous. Which in turn means greater alertness throughout the trip.

Whatever the rig, it’ll come back to operator awareness. Don’t think you’ll overcome Rig deficiencies by brute force.

Awareness is diminished with higher speeds. It is NEVER acceptable to be surrounded by others. Cancel cruise and let the idiots sort themselves. Etc.

The vision problem INCREASES with greater speed. Peripheral awareness decreases radically. The “cone of awareness “ shrinks to what’s in front of one.

Too fast if you aren’t aware of changes in the land as they appear. Grasses, soil, etc.

We ease along, manage the idiots to get gone, and reserve our strength.

The framework for this is to execute legs of a trip. One waypoint to another. Plan the stops (same direction of travel, fewest steering inputs to park and then depart, etc). Two hours between breaks is a professional rule. At four hours need a one hour break.

This is how you keep your actions consistent.

Aero is HIGHLY dependent on discipline. The discipline of a higher state of mechanical condition, and the discipline of rules by which to drive. “All cruise control, all the time”, is that example (as too high a speed relative to traffic cuts into it; changing lanes one must cancel it; overtaking too much traffic means cancellation, etc).

There’s a sweet spot in all things: Lane-centered at a dead-steady speed, is where it happens. (Not otherwise).

Now. How embarrassed would you be if I slid into the drivers seat of your truck and proceeded to get better MPG than you? All as above. No differences in rules. A rig I’ve never driven. (I run away from Fords. �� ).

The difference between us is that I’ve been practicing the above for a long time. All I have to do is figure the glide rate of your combined Rig (when off cruise, how long until throttle needed?). Roads you know, but I don’t. Etc.

When I do, it’s in the bag. And I will.

You understand this isn’t about me or you. It’s “listening” to what the truck tells us it wants. We work for the truck. The lowest fuel burn.

Let it drag a little on grades. Roll the downslope slower. Etc. Doesn’t change the trip. Sure as hell changes the fuel burn.

I figure out that roll, you’re toast.

THE TRIP PLAN is likeliest where you’d fail. Poor planning predicts piss-poor performance (greater fuel burn). This is what separates truck drivers. We have to stay two days ahead.

Have a great trip!

And post us a picture with a report afterwards: scale tickets; number of accel & decel events; engine hours against days miles; etc. The more you do as I’ve suggested (some is required) the more obvious it will be to you what you want to do next trip.


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FWIW, I knew what I was doing when I chose both my pickup and my travel trailer. A lifetime of experience this design of RV.

In the South Central US and at the same speed where I don’t fall below 24-mpg solo, loaded (no matter weather or traffic), I can get my 17,000-lb, 63-foot long combined rig down the highway at an AVERAGE of 15-mpg. Which is lower than prediction. Should be at 17 (I have work to do).

I’ll bet you don’t know WHAT your Ferd is capable of. Steady-state 60-mph and never off cruise control. About 200 miles in a round trip to the same fuel pump. This test would have the same result no matter who’s driving. Is the point. Is how one tests changes.

The day you do this you’ll have the most important baseline number you can acquire for FE

Of course it doesn’t matter any comparison to mine. Plenty of differences exist between truck specification.

The competition is against ourselves.

Pulling a travel trailer SHOULD result in a 40% fuel burn penalty. Which could be improved. But any higher and we KNOW mechanical problems are waiting to be discovered.

AND we have our goal for city numbers. Which has no aero penalty.

SHOULD see almost the same MPG. If not, why not?

Which is my whole point in this post:

The Holy Ghost number

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So to clarify I did not mean to flat out say im better than most at driving but I drive more cautiously than the majority around me. I have an older brake controller than I have learned my way around for the various goosenecks, 5th wheels, and bumper pull trailers so I feel good enough about its abilities. Sure I could spend an extra $150 for a new controller and wire harness but nah.

As far as tongue weight, tire pressure, balance, all the good and bad about weight distribution of a pickup I have a decent understanding. But A 7.3l v8 will not reach the fuel economy of a straight 6 5.9 cummins without major changes. I barley got 19.5 with a tonneau cover on stock suspension about a 3in rake in the rear with 265/75r16 highway tires.

Now I run a level kit up front with 285/75r16 BFG AT2 tires. I raised my front end up just over 3inches to make the truck level, and added taller/wider/heavier tires. I can get close to 18 empty with the tonneau cover and easy highway driving now and that's really, really working my eco driving skills and only in summer. even with diesel kleen and winter fuel blend I am usually 2mpg less average. plus the snow/road conditions and sometimes needing 4x4 or little aired down tires etc.

Regarding towing. The side by side weighs 1720lbs empty with just gear/and fuel and the trailer weighs a hair under that. My truck on the cat scale with no passengers, just truck close to full tank as I can get and the gear is just under 8klbs. I'll never put the trailer on a scale to get the tongue weight totally perfect... its just not worth all the time. I have been eyeing the position on trailers for years without any negative effects. if I start driving and feel my brake test arnt good enough it takes 5 minutes to unstrap and move the unit a tad bit closer to the front etc. You can plan and plan and plan where to strategically place all the camping gear and food in a 5th wheel and still not be at the most effective pin weight. Im very conservative when towing. I try to almost never exceed the manufacture recommendations for weight limits, I have the over load top spring, front/rear sway bars, 3750 max rated tires very rarely ever needed above 70 of the max 80 psi, a very well maintained front suspension/rear suspension, brakes, steering, ball joints, drag link, track bar, bearings, blah blah. I get it im not an over the road trucker with 10 million miles towing rvs but generally speaking a little side by side and maybe 1500ish lb trailer behind 8k is going to be fine. I check tire pressure, grease bearings, adjust brakes, keep good distance (seems relative to each person these days) and I just plain take care of my equipment. I can only drive as good as I can and hope I can react quick enough to react to my mistake or someone else's.


to get back on the point. Im out of state working for the week but soon as I get pictures. looking for feed back on the trailer set up if any mods would be affordable/worth it on the trailer unit.

Perhaps:

The angle would need to be a curve that ends flat for best airflow IMO, kind of like the way the streamlining template shows.

From the speed discussions, trailer tires are rated for 65 mph unless otherwise noted. That is really not fast. Some may be M rated for 81 mph. If the trailer is near max load for the tires, I would try to stick to 60 mph. I used to work at a tire shop, and probably 70% of trailer tires that we replaced(the ones coming off, not going on!) had a tread separation or catastrophic failure from underinflation/excessive age. Treat them as you would with car tires, replace if 6 years or older, or if cracking badly/out of round, etc.

The problem with the truck mounted wing is that it increases lift at the front of the trailer, less stability. I think hucho’s book has lift measurements. I’ll have to check.

I’ve got hucho’s book on road vehicle aerodynamics, pretty sure it’s in there. I could look, but not until tomorrow.

Yes, the Curve would be best, but hard to make. The forward mounted vee would be an improvement over your sketch, and could house tools and maybe a spare tire.Acone mounted to the back of your cargo would help cut drag.

I'm reserving judgment until we see the UTV and trailer together. Those side view don't say anything.

I've been running a '96 7.3 F250 automatic since I bought it new 20 years ago. When I towed a 1967 27-foot aerodynamic Airstream travel trailer with the truck, I could get 15 - 17 mpg running at 55-60 mph. In 2006, I sold the Airstream and bought a new but squarish 27-foot Jayco travel trailer, and with it I average 14 mpg. I sold the Airstream even though it was more economic to pull because it was aging out and needed a lot of work. So, I bought a new Jayco for about a quarter of the price of a new Airstream because it was new and smelled good and most important, made the wifey happy. Since I don't pull the thing that much anyway, the tradeoff was well worth it to me.

To help with the fuel economy when pulling the squared-off Jayco, I did put a set of vortex generators (AirTabs) on the back of the trailer. However, I cannot certify any fuel savings. I can say the back of the trailer is cleaner with the AirTabs, and the trailer seems a little bit more stable in the wind and among the big trucks. In addition, I also attached a wing on the back of a campertop on the F250. Again, I can't certify whether there is any fuel savings or not. There may be some improvements over the long haul, but the difference is certainly not stark like there is between pulling the rounded Airstream compared to the squared Jayco.

I used to be proud that my big ole F250 diesel was among the most fuel efficient travel-trailer-hauling trucks out there loaded to the gills with camping junk. Then came the little diesels on the market that can achieve maybe 20 mpg towing, and my vanity has dissipated accordingly.

Yep, gotta have all the factors in place before making calculations.

perhaps
 

Really can't tell.They're both extremely mutilated forms as a unit.I'd be going with an inflated,bulbous nose ahead of the cargo.I might even enclose the cargo in a zippered,inflated envelope.boat-tailed if possible.

I do have this thing sitting beside the house my wife is THRILLED about. My buddy took it off the semi truck he is using to tow a big 5th wheel around the country as it made his truck too tall and the 5th wheel had it's own nicely shaped front anyway. It is 8' wide and would make a great aero nose for a ATV or snowmobile trailer assuming it was 8' wide.

I'm not far away in Missoula if you wanted to come and get it, I'm not going to be able to use it anytime soon.

https://ecomodder.com/forum/member-h...421-125835.jpg

His trailer it probably close to that width. He could mount it so it partially overhangs the trailer tongue and have a covered from support structure to provide some storage and a nice smooth bulbous nose to get some amount of attached airflow.

I remember you posting this picture a while back (a few years ago I think) on another thread, but couldn't remember your name. I'm kinda surprised you stil have it, figured the wife would have made you toss it by now.

I only got it this spring. My utility trailer is only 5' wide, I think it would hurt more than help unless 8' wide or you could probably cut a section out of the middle to make it narrower. I also figured put it as close to the hitch as possible while still allowing turning and then skin the bottom. If it's not tall enough then build up a box to put it on, it would actually be perfect for sleds with the skis slid up underneath. You could also add hinged panels to the top and sides that form a kham back but move out of the way for loading.