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slowmover · 04-14-2014, 10:31 AM

Slowmover - I found a previous thread about travel trailers. One thing which struck me was the comment that anything above 48" gap between tow vehicle and trailer negates any benefit of the tow vehicle aerodynamics, you might as well be pulling the trailer next to you. If that's the case I'm not sure there is much I can reasonably do to close that gap or improve the combination, other than going with a smaller tow vehicle with a smaller frontal area, like a Roadmaster or Magnum wagon.

The gap problem is real. But it is back to records to put it all into perspective that matters. One is looking for changes to the average annual fuel consumption, and then as a percentage improvement. One does so by first trip-planning: 1] whether weekly errands combined into one trip and trip route optimized, then driving the remaining miles as best as possible; or, [2] with towing miles which is really control over stops once past travel speed decision as accel/decel events matter.

Towing miles are a subset of annual fuel consumption. Easy to break out. But no truck will provide good numbers, and, handicapped as it is for solo or towing stability, a loser to spend on in order to save be it fuel or extending TV component life. There will not be a silk purse from a sows ear. A 300 Hemi is a far better choice, but stick with HD suspension/touring options. A live axle Buick is not the right choice.

All of which is why I'd say to stick with optimizing the articulated rig n the meantime. Get those numbers ideal. Spring for the better hitch as the gap between a VPP hitch and any other is a difference so wide as to make all other types obsolete. Work the scale numbers. One wants the fewest steering corrections possible. The least amount of driver input to remain lane-centered and upright.

On the TV tires and brakes should last in excess of 70k. Verify alignment, zero steering slop and zero brake drag. Etc.

TT brakes and axle alignment matter. Bearing preload. New shocks and better load equalizers. Etc. Read John Barca threads in DIY on WOODALLS. Better, convert to torsion axles (read Fred Puhn on vehicle handling dynamics, and/or, all of Andy Thomson online). Steamline and Silver Streak did not upgrade suspensions during the 1960's as did both Airstream and Avion. Fully independent suspension is part of better FE . . most any change that increases "safety" increases FE potential.

Same for tire changes. Nearly none of us are willin to use ST tires any more. Means a conversion from 15" to 16". BFGoodrich Commercial T/A an easy choice. Others, too. See threads with contributions by CapriRacer here and on AIR (also, tire engineer Tireman9 on AIR). A tire wipeout is likely more than $6k in damage.

Get the tire load numbers before and after WD is applied. Set the hitch rigging. Know how your combination should feel with optimized numbers. Then TV tire pressure can be played with slightly. Ideal is NOT too high for the load.

Think of your rig as having a lot of loose nuts and bolts. Get the numbers squared away (plus a btter hitch) and then you'll have a tight rig where decisions behind the wheel don't cause the penalties they do now. "Tolerance stack" is not your friend, IOW.

.

04-14-2014, 10:31 AM	#14 (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	Slowmover - I found a previous thread about travel trailers. One thing which struck me was the comment that anything above 48" gap between tow vehicle and trailer negates any benefit of the tow vehicle aerodynamics, you might as well be pulling the trailer next to you. If that's the case I'm not sure there is much I can reasonably do to close that gap or improve the combination, other than going with a smaller tow vehicle with a smaller frontal area, like a Roadmaster or Magnum wagon. The gap problem is real. But it is back to records to put it all into perspective that matters. One is looking for changes to the average annual fuel consumption, and then as a percentage improvement. One does so by first trip-planning: 1] whether weekly errands combined into one trip and trip route optimized, then driving the remaining miles as best as possible; or, [2] with towing miles which is really control over stops once past travel speed decision as accel/decel events matter. Towing miles are a subset of annual fuel consumption. Easy to break out. But no truck will provide good numbers, and, handicapped as it is for solo or towing stability, a loser to spend on in order to save be it fuel or extending TV component life. There will not be a silk purse from a sows ear. A 300 Hemi is a far better choice, but stick with HD suspension/touring options. A live axle Buick is not the right choice. All of which is why I'd say to stick with optimizing the articulated rig n the meantime. Get those numbers ideal. Spring for the better hitch as the gap between a VPP hitch and any other is a difference so wide as to make all other types obsolete. Work the scale numbers. One wants the fewest steering corrections possible. The least amount of driver input to remain lane-centered and upright. On the TV tires and brakes should last in excess of 70k. Verify alignment, zero steering slop and zero brake drag. Etc. TT brakes and axle alignment matter. Bearing preload. New shocks and better load equalizers. Etc. Read John Barca threads in DIY on WOODALLS. Better, convert to torsion axles (read Fred Puhn on vehicle handling dynamics, and/or, all of Andy Thomson online). Steamline and Silver Streak did not upgrade suspensions during the 1960's as did both Airstream and Avion. Fully independent suspension is part of better FE . . most any change that increases "safety" increases FE potential. Same for tire changes. Nearly none of us are willin to use ST tires any more. Means a conversion from 15" to 16". BFGoodrich Commercial T/A an easy choice. Others, too. See threads with contributions by CapriRacer here and on AIR (also, tire engineer Tireman9 on AIR). A tire wipeout is likely more than $6k in damage. Get the tire load numbers before and after WD is applied. Set the hitch rigging. Know how your combination should feel with optimized numbers. Then TV tire pressure can be played with slightly. Ideal is NOT too high for the load. Think of your rig as having a lot of loose nuts and bolts. Get the numbers squared away (plus a btter hitch) and then you'll have a tight rig where decisions behind the wheel don't cause the penalties they do now. "Tolerance stack" is not your friend, IOW. .