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Old 02-08-2015, 03:04 PM   #5 (permalink)
Join Date: Oct 2009
Location: Fort Worth, Texas
Posts: 2,442

2004 CTD - '04 DODGE RAM 2500 SLT
Team Cummins
90 day: 19.36 mpg (US)
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Was reading about these today. The pdf download on "tech" is worthwhile for discussion and images in re aero only. Recommended!

I'd like to try the system on my travel trailer. Especially the wings. Expense would have to considered, thus a ways down on what the combined rig has to have, first, and then the list of wants. Having a full ON dork attack is muted by lack of spare cash, thankfully.

One 5er owner on WOODALLS reports 4-5%, but one has the impression that testing is made difficult by few annual miles and any protocol. He's moved to a conventionally hitched toy hauler, and I pity anyone trying to replicate testing with one of those. ("But, dear, I'm gonna save the whales, make Jesus fig tree fruit, and my johnson will be longer. Just need to interrupt another vacation trip with two more hours at the truck stop scales").

That said, were my high average of 16-mpg for the combined rig improved by 7.86%, then it would look to be worth a full mpg. More a bragging rights thing (as with testing empty trucks around here). Reducing tire loads is what any of this is about on this forum, and a loaded pickup is that balance between understeer and FE, plus wind or lateral stability. A trailer, even more so.

OTOH, were crosswind stability improved (reduction of steering inputs in number and time duration), then driver fatigue reduction would be the worthwhile metric to assign. Accident risk minimizing also weighs highly.

As my hitch type ready nearly eliminates trailer sideways movement, I'd be willing to declare these a success by installation on the pickup and bed shell as there is no question of heightened interaction of winds between truck rear and trailer front. The adverse winds affecting the driver in that instance. Even at below highway speeds this is noticeable due to the sail area of a crew cab 3/4T with 8' bed and full bed shell. Were that force ameliorated, it'd be a winner in my book. I also live in one of the windiest regions of the country.

I've already installed a rear antiroll bar (and upsized the front) with a rear Panhard Rod to be done soon for this problem. Enormous improvement while solo. I'd think anyone around this forum is already sensitive to vehicle handling.

My 2WD truck has rack & pinion steering with IFS. A 4WD tends to have crap steering and live axle. Anyone reading other testing with pickups will have a hard time separating traction-tire tread-squirm and dead steering "noise" out of the way. Five percent or more will be difficult to quantify. Then come the usual problems of alignment, caliper drag, and uneven loading. Minute leaks in TC systems. Same for trailer. Needs alignment to less than quarter-inch even rand new. Brake drag and bearing pre-set cannot be assumed. Etc.

Same kind of problem for the usual squared trailer of any hitch type. They ride too high. Ground clearance allows a pair of dogs fighting to barely slow down going under one. My neighbors big 5'er is at 25" GC and mine is a hair under 17". I'd try skirting a non aero trailer, first. That 28% drag factor is gigantic.

Unlike my older TT shown in sig link, the current model has a front like the Brenderup horse trailers. Skin trails back from a mid height nose. A shallow V-section. Tail is identical. Might make for some interesting placement re the Vorblades wing, etc.

Fun to play with the idea, any way. Just gotta do like the smart guys and put on my BZP hat then tune the aerial with the Freebeard antenna analyzer to Radio Aerohead.

Last edited by slowmover; 02-08-2015 at 04:34 PM..
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