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slowmover · 09-06-2010, 12:53 PM

Cap on the tow vehicle if it's a pickup. The closer it matches the trailer height the better.

Huh? The tow vehicle and trailer are more than 30" apart. Treat each vehicle separately is the only choice. There won't be a way to reduce that gap and the trailer needs the space on tight turns. Might as well work on a degree in Redneck by hittin' the boneyard for a shiny ol' chrome wing to mount on the cab. And chicken lights.

Running 75? No way that combination can be handled safely. This is foolishness. The posted speed limit is, itself, too high for a rig like this. A classic example of "speeding, under the limit". And I'd sure like to see proof of better fuel economy at 75 (so would Detroit, Cummins, Peterbilt, etc).

Don't feel the passing trucks as much? Hitch rigging is not correct (and tire pressure on both vehicles is suspect). Where are the scale readings which show the hitch rigging verification?

3-4 mpg better? Questionable record keeping is likely. What is the percentage change is what matters AND over how many miles (and details about altitude, trailer weight, general weather, etc, apply).

This discussion -- enclosed trailer fuel economy improvements -- is too narrow a focus if one is contemplating ROI (return on investment). Trailer towing so significantly changes the dynamics of driving that, for a given trailer and tow vehicle, the best money spent is in perfecting trailer tires, trailer brake performance, hitch rigging, and TV/Trailer electrical. Fuel economy is only a sub-set of Economy and focusing on FE first is putting the cart before the horse.

If one trailer allows for 18 mpg behind a given vehicle, but another allows 12 mpg yet lasts twice as long, has better brakes/suspension and is capable of better skidpad numbers . . . and the use is predicated on only 10k annually (or more, or less), the second trailer is a FAR better choice.

First, what is the best trailer to study? Easy, the U-Haul 6'x6'x12' enclosed trailer. (In private use this trailer would NEVER wear out).

U-Haul: Equipment specs

Short, narrow, close-to-the-ground; outstanding construction and design, rounded edges and corners. Will live forever under abusive conditions. What does it need for better fuel economy? Little, as improved suspension and brakes (independent and disc, respectively) are worth FAR MORE than a nosecone or trailing edge device. One might round the corners/edges more, but trade-offs in capacity must be known first. It must also be suitable for a weight-distribution hitch as proper hitch rigging -- the effect of the trailer upon the tow vehicle -- has more of an effect on Economy than do aerodynamics (the costs of poor road performance).

Then, and only then, do aero aids begin to justify their expense.

Money spent on an off-the-lot conventional trailer should be spent towards safety: hitch rigging, tires, braking, handling, lighting; then longevity (method of storage & maintenance), THEN fuel economy. Build standards are low -- throughout this and the RV industry -- and corrections should be made.

The following should be part of any trailer towing kit:

- SHERLINE Tongue Scale
Sherline Trailer Tongue Weight Scales

- Dedicated Torque Wrench
Ace® Torque Wrench - Specialty Wrenches - Ace Hardware

- Tire pressure gauge (trash low quality ones)
QUICKCAR TIRE PRESSURE GAUGES

- Locking Wheel chocks (if tandem axle)
Fastway OneStep Wheel Chock System for Tandem Axle Trailers and Fifth Wheels

- Laminated wheel chocks (need enough for both vehicles)
LAMINATED WHEEL CHOCK at Material Handling Solutions

- Tires
On The Wings of Goodyear | RV Tires - Tire Selection - Marathon®

- Brakes
Dexter Axle - Trailer Axles and Running Gear Components - 3.5K Disc Brake Retrofit Kit - LH

- Brake Controller
http://www.maxbrake.com/brake-controller.php

- Shock Absorbers
Monroe Trailer Retrofit Kit - Shockwarehouse.com

- LED signal/clearance lamps
Super Bright LEDs ? Clearance, Marker and Tail Lights for Trucks

- Upgrade tow vehicle electrical
http://forum.sounddomain.com/ubbthre...page/1/fpart/1

- MODULITE
Upgraded Modulite Circuit Protected Vehicle Wiring Harness with 4 Pole Trailer Connector Tow Ready Wiring 119176
Information on Modulites

- Trailer brake re-wire
RV.Net Open Roads Forum: Towing: Independent Brake Wire Feed Upgrade

And so forth.

ANY one of these -- dollar for dollar -- is worth more than add-on aero devices. And, if the trailer is at 2500-lbs or above (or at the weight where a weight-distribution hitch is required for a given vehicle [and NONE are exempt, including the heaviest pickup]) then hitch rigging is paramount.

Frankly, a study of how to drive for economy -- while towing -- is time/money better spent than tack-on aero aids. The return is greater, the $$ are lower, and it is subsumed under what truck drivers know as "trip planning". The details of how to accelerate, what pace to maintain, what braking distances, when to get off the road, what kind of roads, etc, etc, are more fruitful.

So here are two questions:

1] In what manner will a blunt-front trailer's performance improve with aero add ons?

2] In what manner will it DECREASE? (for it will)

.

09-06-2010, 12:53 PM	#4 (permalink)
slowmover Banned 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) Thanks: 1,422 Thanked 737 Times in 557 Posts	*Cap on the tow vehicle if it's a pickup. The closer it matches the trailer height the better.* Huh? The tow vehicle and trailer are more than 30" apart. Treat each vehicle separately is the only choice. There won't be a way to reduce that gap and the trailer needs the space on tight turns. Might as well work on a degree in Redneck by hittin' the boneyard for a shiny ol' chrome wing to mount on the cab. And chicken lights. Running 75? No way that combination can be handled safely. This is foolishness. The posted speed limit is, itself, too high for a rig like this. A classic example of "speeding, under the limit". And I'd sure like to see proof of better fuel economy at 75 (so would Detroit, Cummins, Peterbilt, etc). Don't feel the passing trucks as much? Hitch rigging is not correct (and tire pressure on both vehicles is suspect). Where are the scale readings which show the hitch rigging verification? 3-4 mpg better? Questionable record keeping is likely. What is the percentage change is what matters AND over how many miles (and details about altitude, trailer weight, general weather, etc, apply). This discussion -- enclosed trailer fuel economy improvements -- is too narrow a focus if one is contemplating ROI (return on investment). Trailer towing so significantly changes the dynamics of driving that, for a given trailer and tow vehicle, the best money spent is in perfecting trailer tires, trailer brake performance, hitch rigging, and TV/Trailer electrical. Fuel economy is only a sub-set of Economy and focusing on FE first is putting the cart before the horse. If one trailer allows for 18 mpg behind a given vehicle, but another allows 12 mpg yet lasts twice as long, has better brakes/suspension and is capable of better skidpad numbers . . . and the use is predicated on only 10k annually (or more, or less), the second trailer is a FAR better choice. First, what is the best trailer to study? Easy, the U-Haul 6'x6'x12' enclosed trailer. (In private use this trailer would NEVER wear out). U-Haul: Equipment specs Short, narrow, close-to-the-ground; outstanding construction and design, rounded edges and corners. Will live forever under abusive conditions. What does it need for better fuel economy? Little, as improved suspension and brakes (independent and disc, respectively) are worth FAR MORE than a nosecone or trailing edge device. One might round the corners/edges more, but trade-offs in capacity must be known first. It must also be suitable for a weight-distribution hitch as proper hitch rigging -- the effect of the trailer upon the tow vehicle -- has more of an effect on Economy than do aerodynamics (the costs of poor road performance). Then, and only then, do aero aids begin to justify their expense. Money spent on an off-the-lot conventional trailer should be spent towards safety: hitch rigging, tires, braking, handling, lighting; then longevity (method of storage & maintenance), THEN fuel economy. Build standards are low -- throughout this and the RV industry -- and corrections should be made. The following should be part of any trailer towing kit: - SHERLINE Tongue Scale Sherline Trailer Tongue Weight Scales - Dedicated Torque Wrench Ace® Torque Wrench - Specialty Wrenches - Ace Hardware - Tire pressure gauge (trash low quality ones) QUICKCAR TIRE PRESSURE GAUGES - Locking Wheel chocks (if tandem axle) Fastway OneStep Wheel Chock System for Tandem Axle Trailers and Fifth Wheels - Laminated wheel chocks (need enough for both vehicles) LAMINATED WHEEL CHOCK at Material Handling Solutions - Tires On The Wings of Goodyear \| RV Tires - Tire Selection - Marathon® - Brakes Dexter Axle - Trailer Axles and Running Gear Components - 3.5K Disc Brake Retrofit Kit - LH - Brake Controller http://www.maxbrake.com/brake-controller.php - Shock Absorbers Monroe Trailer Retrofit Kit - Shockwarehouse.com - LED signal/clearance lamps Super Bright LEDs ? Clearance, Marker and Tail Lights for Trucks - Upgrade tow vehicle electrical http://forum.sounddomain.com/ubbthre...page/1/fpart/1 - MODULITE Upgraded Modulite Circuit Protected Vehicle Wiring Harness with 4 Pole Trailer Connector Tow Ready Wiring 119176 Information on Modulites - Trailer brake re-wire RV.Net Open Roads Forum: Towing: Independent Brake Wire Feed Upgrade And so forth. ANY one of these -- dollar for dollar -- is worth more than add-on aero devices. And, if the trailer is at 2500-lbs or above (or at the weight where a weight-distribution hitch is required for a given vehicle [and NONE are exempt, including the heaviest pickup]) then hitch rigging is paramount. Frankly, a study of how to drive for economy -- while towing -- is time/money better spent than tack-on aero aids. The return is greater, the $$ are lower, and it is subsumed under what truck drivers know as "trip planning". The details of how to accelerate, what pace to maintain, what braking distances, when to get off the road, what kind of roads, etc, etc, are more fruitful. So here are two questions: 1] In what manner will a blunt-front trailer's performance improve with aero add ons? 2] In what manner will it DECREASE? (for it will) . Last edited by slowmover; 09-06-2010 at 01:06 PM..