Offroad trailer Vs Roof tent MPG

[Poorboyota26]

Bingo! On a day trip you just throw a back pack and a cooler in the back.

On an extended trip, you can hook up the trailer with all of your extended trip gear in it and go. If your RTT is on the trailer then you only loose the mileage when the trailer is hooked up. Increasing your fuel mileage in the longterm/big picture (the entire time you ownt the vehicle).
:smiley_drive:

The downside is that you have to find a place to store your trailer when not in use, and the initial cost of the trailer. Many here have built their own but it still costs 500-1500 from scratch. You wont recover those costs for years. I wouldn't trade my trailer though I use it for utility purposes as well as getting out in the wilderness.

 

[teotwaki]

---snip----

I believe it was Tom Sheppard who said that the big racks are illogical, and people are really only doing it for the "serious explorer look".

I never read anything like that (understand that memories are tricky) but what I did read in his various tomes was invariably both factual and logical:

1. If you can avoid roof racks, do so because of wind resistance issues, CG impacts and even possible weakening of the vehicle's structure
   
2. If you have a roof rack you should place the lighter weight and bulky items up there in order to regain interior space.
   
3. Don't let the use of a roof rack lead you to exceed the vehicle's GVW.

In Desert Expeditions he did say "....a trailer is a better solution than external racks"

 

[cnynrat]

Going down hill it actually puts fuel back into you tank (or so it says on all of our sales literature) :sombrero:

So if I could manage to plan all my trips to be all downhill I'd be in the gasoline business. :victory:

Seriously, I saw that affect this past weekend on the Mojave trail. The first couple days were quite a bit of up and down, but mostly up. Sunday we started from the Beale Mts which made the day mostly downhill, and subjectively I think my gas mileage reflected that.

 

[R_Lefebvre]

I never read anything like that (understand that memories are tricky) but what I did read in his various tomes was invariably both factual and logical:

1. If you can avoid roof racks, do so because of wind resistance issues, CG impacts and even possible weakening of the vehicle's structure
   
2. If you have a roof rack you should place the lighter weight and bulky items up there in order to regain interior space.
   
3. Don't let the use of a roof rack lead you to exceed the vehicle's GVW.

In Desert Expeditions he did say "....a trailer is a better solution than external racks"

Yes, all of that, plus he made a comment like what I stated. IIRC, it's in the Winter 2008 issue of OJ, the article about loading vehicles. I'll try to get the exact quote tonight.

 

[R_Lefebvre]

Ok, OJ 2008 Gear Guide, Pg. 104, Tom Sheppard:

Worst of all, the high CG problem is massively exacerbated by fans of the Explorer Image, in which there is not only a roof rack, but one burdened with the highest density load you have: water and fuel cans. And probably for good measure a set of sand planks (steel of course). It will stay with me forever, like a mental Polaroid, but I once saw a Defender with 18 cans on the roof.

.....

A sub-industry of interior/exterior scaffolding blossomed in an attempt to retroactively correct the issues and add glitz to what has now become the Serious Explorer Image.

I'm glad he said it first, and not me.

 

[Redline]

Yep! ☺ I’ve done this many times with good results, both with and without trailers.

snip......

If you're in an area with rolling hills, I like to build up a head of steam on the backside, and then "coast" up the next hill. I'll exceed the speed limit within reason, building speed with the throttle less than 1/2 way, so that I can climb the next hill at less than 1/2 throttle, bleeding off speed.

Obviously this all takes some extra effort, but it pays off.

 

[DaktariEd]

I had my Maggiolina on the top of my FJ40 and lost about 2 mpg.
After moving it to my Horizon Adventure trailer, I got most of my mileage back!

 

[teotwaki]

Rob, thanks for researching and typing up the quote from the OJ magazine. I don't subscribe to OJ but occaisionally scam free copies. :sombrero:

Worst of all, the high CG problem is massively exacerbated by fans of the Explorer Image, in which there is not only a roof rack, but one burdened with the highest density load you have: water and fuel cans. And probably for good measure a set of sand planks (steel of course). It will stay with me forever, like a mental Polaroid, but I once saw a Defender with 18 cans on the roof.
.....
A sub-industry of interior/exterior scaffolding blossomed in an attempt to retroactively correct the issues and add glitz to what has now become the Serious Explorer Image.

I see this quote as entirely consistent with his earlier writings that I summarized in the 3 points in my previous post. He never said that racks were "illogical" or inherently bad. He did actually say a trailer was a better choice but never said it was the only choice. In the above quote he reaffirms the blatant misuse of racks through thoughtless overloading and the dangerous raising of a vehicle's CG.

If anything, it is pretentiousness that he definitely abhors (Explorer image), not the use of roof racks. Just look at what he said about clothing in the RGS Expedition Handbook

No points are awarded for the ragged explorer image of old and, although modern technical clothing favours the baggy look for sound practical reasons, there is no excuse for it not to be clean or for you not to have a set of “presentables” in your bag too. Appearing at customs posts, campsites or hotels looking like a vagrant does no one any favours.

If you read more of his writings you'll see the themes that he interwaves with his facts.

In Four-By-Four Driving he says:

Roof racks and the explorer image seem, alas, to go hand in hand, but, as covered in Section 8.1, avoid roof racks in off-road vehicles if at all possible. If you do have a major storage problem, use roofracks only for featherweight items like sleeping bags, tents and the like; not for heavy items like fuel cans...

Interpreting just one OJ article is not enough to get a sense of what he espouses and what it is based upon. He is well qualified to look down upon pretenders and overloaded roof racks are a tip off for him, but not just the use of roof rack.

All that aside, I want to have both the trailer and a roof rack, but only the trailer presents a storage problem for me. :elkgrin:

EDIT: also see Expedition Guide 2.1 2nd Edition sections 1.2-9 & 10 and 4.3-26 & 27

 

[R_Lefebvre]

Rob, thanks for researching and typing up the quote from the OJ magazine. I don't subscribe to OJ but occaisionally scam free copies.

I actually just bought the back issues from 2008 and 9. Slowly working through them. I have VDEG but haven't worked through it yet. Well, I've cherry picked and read a few sections. If you have all the other books, you'll probably enjoy OJ. I particularly like the indepth and timely relevance of the gear reviews. Sometimes a book is designed with longevity in mind, and discussion of gear is too general, and not specific enough. For example, I was really interested in one of the water purifiers, until I read the report from OJ that showed it was actually ineffective.

I think his stance on the issue of racks is pretty solid. I mean... it's not absolute, it's rational. He says it avoid if possible, and if you must, only put light things up there. Pretty reasonable. As far as the Explorer Image, I think it's something most of us are guilty of to some degree. I have a lot more green, beige and brown clothing since I bought my truck. But there's nothing wrong with that. I think if people really want a rack because they like it, and can admit that, and are reasonable in how they use it.... whatever floats your boat. There's another group of people who abhor trailers, I think because of the association with RVing or trailer trash, I dunno, and are all about the roof rack with tons of fuel on top because that's the "proper" thing to do. I think that disingenuous.

As much as I wanted to avoid roof racks, I'm going to have to do something to carry my canoe, and bridging ladders.

Now, the only thing about Mr. Sheppard's recommendations that I take issue with, is the storing of fuel INSIDE the vehicle. I come from a performance car background, where fuel in the vehicle is taken VERY seriously. If you EVER have to move a fuel tank into the vehicle, you must use an expensive and complicated leak-proof fuel cell. You'd never be allowed on a race track or rally with a single-walled steel fuel tank bungy corded into the back of your car. So I really question that approach. I prefer to keep my fuel outside the vehicle.

 

[R_Lefebvre]

Yep! ☺ I’ve done this many times with good results, both with and without trailers.

I find it's not worth the effort when I'm not hauling the trailer. It's probably a case-by-base basis. My particular truck has enough power to go up most hills at the speed limit without kicking down a gear or going past 1/2 throttle. If a particular truck is more... lightly powered... it might make more sense to do it when not towing a trailer.

Another point about trailers... and this is just my untested hypothesis at this point... some anti-trailer people state that a trailer will prevent you from running a trail that you otherwise could, if you instead stored your gear on a roof rack. This, because with a trailer, you have all that weight on top of an unpowered axle.

I think that if one were to resist the urge to pack the the kitchen sink into the trailer just because you CAN. If you simply take your roof load, and move it into a very light and smartly built trailer, so you're talking about towing only 5-900 pounds... that the drag from the trailer is so little, you could run the same trails you could with a heavily loaded roof rack. Having several hundred pounds on your roof is it's own limitation.

 

[KLAKEBRONCO]

There is an entire thread on here about roof racks, with much of it talking about ways to prevent MPG loss. Most that can be done however, is a method of saving fuel when using the rack alone. As soon as things are put IN the rack those go out the window.

I would like a rack on the Bronco because I think I would without question use it. But this is an issue of family/vehicle size.

 

[JIMBO]

:sombrero: I'm not arguing with any of Mr. Sheppards ideas and I never carry any cans of ANYTHING on top

Just my bulky tent/bags/tarps-etc

This shot is from last May, above Lake Donner

Because it's an MBRP JK rack, sitting back, on the hardtop, there's no noise and negligible mileage effect !!

:costumed-smiley-007:costumed-smiley-007 JIMBO

 

[Redline]

I find it's not worth the effort when I'm not hauling the trailer. It's probably a case-by-base basis. My particular truck has enough power to go up most hills at the speed limit without kicking down a gear or going past 1/2 throttle. If a particular truck is more... lightly powered... it might make more sense to do it when not towing a trailer.

Yes, I think you're correct. When my 4Runner was still geared tall with the stock 3.73s I could obtain some very good MPG using this method. If I didn't the tranny/torque converter would kick out of lock-up far too easily. Now with 4.88s it's much less of an issue and I find myself not trying as hard to drive it gently, though that's how I normally drive.

Another point about trailers... and this is just my untested hypothesis at this point... some anti-trailer people state that a trailer will prevent you from running a trail that you otherwise could, if you instead stored your gear on a roof rack. This, because with a trailer, you have all that weight on top of an unpowered axle.

I think that if one were to resist the urge to pack the the kitchen sink into the trailer just because you CAN. If you simply take your roof load, and move it into a very light and smartly built trailer, so you're talking about towing only 5-900 pounds... that the drag from the trailer is so little, you could run the same trails you could with a heavily loaded roof rack. Having several hundred pounds on your roof is it's own limitation.

Your theory is possibly largely correct, except that while having a roof rack full of gear is mostly a COG negative, it doesn't necessarily put a 'drag' on traction. In fact it mostly helps with increasing contact pressure (firm ground). Of course I can't help prove or test the theory as both of my off-highway trailers have been fairly heavy when loaded for a trip. Other negatives of towing trailers is their impact on size and maneuverability, but I certainly have liked and enjoyed my off-road trailers.

Though not an apples to apples test as suggested here (trailer with RTT vs. just RTT), I would surely like to test the MPG of my 4Runner loaded for a big trip with my new RTT installed, then with the RTT off and my Kimberley Kamper in tow.

 

[DrMoab]

I would love to not need a trailer. My problem is I have a relatively small vehicle (a jeep cherokee) and I always have two kids and a very large dog. Before I bought my RTT I could pack most of my camping gear in a roof rack and keep the back open for the dog. Once I got my tent I realized that I also lost all my packing space on my roof.

 

[R_Lefebvre]

Your theory is possibly largely correct, except that while having a roof rack full of gear is mostly a COG negative, it doesn't necessarily put a 'drag' on traction.

You're right. But part of my theory is that a racked vehicle will be limited to climbs that are still safe based on it's higher COG. A trailered vehicle can probably make those same climbs with a light trailer, because a very high COG vehicle isn't traction limited, it's rollover limited.

And it's not just about climbs. A "difficult" trail will also probably include some off-camber driving, which is a place that a trailer has a huge advantage compared to a rack.