Towing with efficiency

[oil pan 4]

Originally Posted by stillsearching

larrybuck how do you get nearly 30mpg with a 4x4 suburban?? I rarely hear better than 22mpg reported for 2wd.

My 2wd suburban started out getting 21mpg in 2006 in factory configuration when I got it. Also logged 4 tanks towing around 6000lb, got a solid 15mpg all 4 tanks.

I have gotten a 6mpg boost from driving it slow and drafting which put me right about 30mpg, this was factory configuration or close to it.
I dont have nearly that much time so I mod.
Also consider those 30mpg numbers as cheating, at the very least they are unrealistic for day to day highway driving.

Not going to add an hour onto a 4 hour trip just to save between 1 and 2 gallons of fuel.
Or turn what should be a 1 day drive into a 2 day drive just to save maybe 10 gallons of fuel.
I can get more fuel, but can't get more time.

[slowmover]

Above 6500lbs up to 10,000lbs is where i'm trying to get more information basically, how feasible it is.

It's about aero, not weight. If the load is aero (some travel trailers, for instance) or the load is low and fairly narrow on an open trailer, then, yes, minivans (Honda Odyssey) or sedans (V6 Dodge Charger) are both decent candidates with the proper hitch and hitch receiver. Some science goes into this, but CAN AM RV of London, ON has been outfitting all sorts of vehicles to tow these loads [as quoted] quite well for over four decades. In this country, up until about 30 years ago it was more of a norm as well.

Now, if you're going to haul some wind-catching load on an open trailer, then the big horsepower tow vehicles are going to be called for.

It would help to be quite specific in what is to be accomplished. Hauling in some firewood from the local countryside is one thing . . crossing the Rockies on a weekly basis is quite another.

A half-ton truck like the 3.5L V6 FORD Ecoboost is another vehicle from which to make comparisons.

Fuel mileage isn't that important anyway. It's the cost of ownership even more than the cost of operation. The properly spec'd vehicle is the one that lasts the longest for the service envisioned. The occasional towing can be done by a range of vehicles otherwise suitable for commuting/grocery-getting.

Set the target at years/miles of ownership and back your way into things. Same for the trailer, as quality matters highly, here.

.

[slowmover]

Not going to add an hour onto a 4 hour trip just to save between 1 and 2 gallons of fuel.
Or turn what should be a 1 day drive into a 2 day drive just to save maybe 10 gallons of fuel.
I can get more fuel, but can't get more time.


I understand the sentiment. But there is more than one way to look at this. Most folks who make this particular argument are only hurrying to pick up the TV remote control. If lowest cost of ownership is as important as cost of operation, then vehicle longevity (and components such as tires) also have weight to consider. An hour or two is more a matter of proper trip planning than higher travel speed. There is a distinct trade-off to travel speeds higher than 55-mph for more than fuel burn.

Also, let's not think that fuel will always be as cheap or as easily available as it is today. At the very least one would want to know the available range of the combined rig under varying circumstances. This can take a fair amount of testing to verify.

And 10/gls of fuel can pay for a night at an RV park with full hookups in many instances. Etc. Repeated often enough over several hundred thousand miles it is more than significant in direct and indirect dollar savings. Thus the above question about being specific in what is being towed over how many miles, and over a given amount of time is crucial to beginning an answer to Towing with Efficiency.

I have a given rig. The TV [tow vehicle] and TT [travel trailer] won't change. The weight and the aero [stock] are already set. Making it more efficient is mainly a matter of a few dozen mechanical details to iron out. After that comes the most efficient use of fuel (much of which is covered in pickup truck threads here at EM even when the TV is of another type). Then there is experimentation with aero changes. Gearing changes. Time/Effort plus $$ with a payback that may not be "realistic" except for those covering, say, 20k annually with the rig. And over more than 5-years.

This would be quite different than a local salvage hauler. IOW, the details of use matter more than the specifics of the rig (as there is more than one way to skin a cat).

.

[oil pan 4]

Tires is a good point.
Load range C, 31 inch tall tires on 15 inch rims is about as cheap as you can get.
They are plenty tire for a half ton.

I pull an open trailer, no sleeping in it or on it. If its being pulled on a long trip its got stuff on it. I would just sleep in the back of the suburban if I could, and I do when its not full.
If the old lady is with me, she dont go for that.

[stillsearching]

Originally Posted by Frank Lee

Sounds like your CAD guy is the one to ask.

He is but he travels so much the last time I heard from him was 9 months ago and when he is in town he's too busy for detailed talks. :-/ Plus don't know if he will have time/energy (or me the money since i'm guessing it's more than trivial work) to design up similar "beyond normal specs" rigs for other vehicles or how feasible it is... if I scale it up I might find midsize unibody vehicles pulling 5000lbs or so, but that's not quite enough extra to be what i'm looking for. A 30% boost over what the Saturn is known to safely do doesn't radically expand what I can do all that much to justify owning a 2nd vehicle just for that.

However of interest I recently found out the 1993-96 Cadillac Fleetwood with the tow package can pull _7000lbs_ factory rated. Not bad for something getting 23-25mpg highway unladen "driven like an american" (techniques here would probably make that 30mpg), and better than midsize SUV's or 1/2 ton light trucks that it's basically doing the job of. The chassis is almost identical to the Caprice/Impala/Roadmaster line (just a few inches longer, tow ratings without the two package otherwise the same as them) so i'm assuming that those with similar mods are probably safe to tow 7000lbs as well. (the differences are things like bigger radiator, low axle ratio, trans cooler and such. Nobody is uprating frames or anything at that level, the pieces changed for that package are known quantities. The Caprice frames are built reasonably tough - they're used for police and taxi use, driving over curbs and such.) What i'm hoping is maybe a diesel swap into a Caprice with enough power would hopefully exceed the gas engine specs for mileage and especially for laden towing. (instead of dropping to less than half as is typical with gas engines) That's starting to look like my option of choice in this weight class.

If the frames handle 7000lbs towing "from the factory" given the right suspension parts, it's not unsafe and forcing the vehicle to do something it's not designed to do. Obviously it was designed to do that, on the frame level, since it came out in a version to do just that. It just may not have been commonly equipped to do that since most buyers didn't need that.

How much of a stretch it would be for other RWD full frame full size cars to pull 7000lbs i'm curious of too though and still an open topic, given the right upgrades just if there's options. However i'm favoring a bubble Caprice because i'm guessing older ones wont match the aero of the newer ones. (Plus the fact I already have one in the driveway i'm not doing anything useful with. It's not worth much to sell used, so i'm not beyond hacking in diesels and stuff to make it into a tow vehicle and if it worked out well later adapting the custom parts to a Fleetwood when I find one to dieselize it maybe for SVO.) Plus aeromodding the newer ones could well make it even better especially when not trailering.


So this bumps slightly the next big leap between 7500-10,000lbs. It's possible I could briefly tow things slightly entering that with the Caprice shorter range at slower speeds more in that range but I wouldn't want to make a habit of it. Safety demands I get a higher rated vehicle or take more trips if it's a routine thing - don't read me wrong, i'm not stupid. As to why do I want to keep stretching things "just a little further" in part it's about self sufficiency... if I can move everything from my friends lifted probably 7000lb 4x4 on a braked tow dolly probably weighing another 1000lbs if he ever breaks down, to all the common loads I want to be carrying out to a future farm with better mileage, the money savings add up. Instead of paying a $500 long range tow the one time my friend needs that tow he pays me, compensating the other projects, etc. That's a good example of a single load I can't break up into separate trips.

Intermittent heavy single-trip loads (like a vehicle tow, or something like a utility tractor on the flatbed with all it's attachments that I bought from another farmer) i'm not too worried about keeping up with traffic, i'm not planning to be through the mountains, I don't mind stopping if any gauges are showing running hot, and would definately be the exception done maybe 2-3 times per year.

However in all due admissions... the modern pickups may well be a good choice for aeromodding and properly done might well beat a stock Caprice for mileage and might get fairly close to an aeromodded one. Since modern pickups of the last 10 years CAN pull 10k lbs and more safely properly set up, i'll be doing more research into that next I think. (for the future date when the Caprice is found to not be enough/common enough loads over 7000lbs to actually justify having a third vehicle and trailer or saving enough on reduced trips to pay the difference)


slowmover - i'm aware of the aero issue, loads I expect to pull will be mostly lower profile heavy stuff on flatbeds. Bags of concrete, scrap steel, scrap wood, seed/fertilizer (quantities below normal "need a tractor trailer" agribusiness levels), 55 gallon drums, totes of ricehulls, 2-3 cords of wood at once, utility tractors in the 5000lb class (by themself, before trailer and implements also included), an antenna tower if another free one ever shows up on craigslist like last year for ham radio use, an occasional parts car on a tow dolly, etc. No 13.5 ft tall fifth wheel quintuple slide boxes - if I were pulling those the aero of the lead vehicle wouldn't matter and I wouldn't care about aero tow vehicles. Can you tell me more of CAN AM RV? I didn't understand what you meant there, this is your first post here. Other vehicles in the 4-6k class i'm still curious about.

"Total cost of ownership" definately is in the figures, it's actually the reason for researching all my options about this in the first place. The easy answer everyone encourages me to do - buy a pickup and use it like a pickup. But the TCO of that doesn't work right now, ie seeking a full time vehicle dedicated just for towing with that as it's best job. There wont be enough regular heavy loads, with enough time spent always laden to justify that. The loads that are expected will be varying in load up to a few tons, intermittent/totally unpredictable (craigslist freebies in a 500 mile radius I have to jump on, plus occasional planned bulk buys and such), and are best done with dual purpose vehicles that otherwise are just commuters for around town. I have space for two vehicles plus a folding 4x8 trailer in town, heavier use trailers would be rented when needed but I want to tow them with a vehicle that is not just dedicated to towing which gets acceptable mileage unladen, hence my preference for a sedan when possible.

Pickups aren't 100% out, they're just disfavored right now unless plans/expectations/future changes. I'm expecting single unit (cant break up) loads over 7000lbs to be pretty rare but to happen (I gave the example of heavy tow dolly loads and a farm tractor/skid steer with all implements being the only examples I expect in that range, but the several hundreds saved per time by doing it myself to pay for itself), large bulk loads way over 7000lbs needing multiple trips will be rare/infrequent enough that extra trips aren't too burdensome (but 3-5x the trips with the Saturn probably would be a bit burdensome and the extra trips ruining any better mileage advantage by that point) and I can't fit a crew cab in the garage. (moving 6 people sometimes happens for me) So if I can stretch a full size sedan to 8000lbs or so maybe 8500lbs load ability infrequently that pretty much meets everything I can conceive of wanting to do with it.

[stillsearching]

I hope doubleposting is okay, the single monolithic wall of text was looking too big. :P

Originally Posted by slowmover

Not going to add an hour onto a 4 hour trip just to save between 1 and 2 gallons of fuel.
Or turn what should be a 1 day drive into a 2 day drive just to save maybe 10 gallons of fuel.
I can get more fuel, but can't get more time.


I understand the sentiment. But there is more than one way to look at this. Most folks who make this particular argument are only hurrying to pick up the TV remote control.

Well that's them not me. In town for the daily commute I have more money and less time - saving 1/2 gal to extend the commute 30mins isn't worth it, I expect to be commuting to college 1.5hrs per day as it is. I'd rather take slightly more loan for another $100/month to save the time when i'll already arrive home exhausted from a beyond full time load that I expect to be having. The "towing" use will happen on weekends when I run things of opportunity out to a farm (the target where i'm hauling everything to), or during periods off like in summer or during vacation, where I will have more time than money. Running slow sometimes if needed wont bother me, especially if two vehicles stretched a bit in their duties can replace requiring a dedicated tow rig especially one that wastes fuel while running out unladen because of boxy aerodynamics since it probably will be half the time, though some occasional "round robin" pickups of loading a trailer with multiple pickups of different things will try to be done as much as possible.

Originally Posted by slowmover

If lowest cost of ownership is as important as cost of operation, then vehicle longevity (and components such as tires) also have weight to consider.

Also, let's not think that fuel will always be as cheap or as easily available as it is today.

Thus the above question about being specific in what is being towed over how many miles, and over a given amount of time is crucial to beginning an answer to Towing with Efficiency.

IOW, the details of use matter more than the specifics of the rig (as there is more than one way to skin a cat).

I completely agree on all factors, and due to friends in the oil industry full expect radically increased oil prices over the next 8 years (2-3x what we have now easily) and that's actually part of the reason for this extensive research. Everything is going to go into a spreadsheet. Cost to acquire, cost to modify, fuel cost, maintenance cost, expected reliability of the platform, other costs (including the cost of a vehicle spending most of it's time sitting instead of seeing regular use, with the insurance and such to do so marked up). Right now I have "expected loads" I want to haul over the next 8 years or so which i'm planning around. Cheap or free craigslist type stuff that only pays for itself if you can bring it home without excessive transport cost. The character of those loads might change though leading to me reopening all the notes and calculations I did in the future and deciding a different set of vehicles is now more suited for the jobs. For awhile I thought a minivan would be my best second vehicle - that's now changing into a RWD sedan after more research and playing with numbers. As future situation changes that could be replaced by a Chevy Astro, a fullsize superduty pickup of some sort, or back down to an FWD Pontiac Trans Sport and i'll have the numbers backing each choice of when something paid for itself and when it justifies switching.

I'm pretty set on the Saturn as the daily commuter. Mileage is not as good as some even smaller cars like the Geo Metro but having a Geo and a Saturn probably doesn't improve the mileage enough to justify the Geo, and I can't haul any weight worth pulling in the Geo. It's also better put together from a reliability standpoint - more maintenance cost on the Geo starts to kill the issue.

Getting one vehicle to do the job of two is one of the best money savers I can do. There's also nonfinancial things i'm considering. I HAVE to have two working vehicles - I need a backup to know I can always get to work or school on time in event of a problem. I hope to have a motorcycle for even more efficient commuting in town but that's not all season all weather. The trailer storage is free because it folds up in the garage, the weight limit on that is 3500lbs/it will already be custom and they don't make larger folding trailers that i've found so that's another forced limit I design around. More than two cars have to be stored offsite - that's a cost. Or it has to be parked at the future farm - then it's a mileage cost to go pick it up first. I want to experiment with SVO extensively as a fuel (and getting the recycled building supplies for the greenhouse i'll be growing the plants in year round is part of the job here), that requires a diesel anyways, which requires hauling home the parts vehicle i'm pulling it out of. If i'm successfully growing that at the farm that alters fuel costs substantially making me convert other vehicles to it. So the cost to convert to diesel is not always a barrier.

Vehicles I plan to set up I generally plan to have for the long haul. My dad kept cars for 10-20 years and maintained them to run forever, the two I already have are 10 and 20 years old. If they tow what I want, and convert to diesel, and then run off SVO nicely I might well still be driving both in 2040. But I won't do anything if the numbers dont' make sense, and all the extensive research here and exploring of options is what helps me see all the different ways I can go about trying to solve the "lowest total cost of ownership while still getting the job done" problem.


Details of use is why I seem to harp so much on ideas that others may want to discount or think that a rig is unsuitable over. What I really basically need right now is a full size RWD sedan that can safely pull 8500lbs OR possibly an El Camino or minitruck doing the same for best aero, which runs on diesel. That I seem to get *so close* is what makes me look to see what the risks are of slightly stretching things or tweaking little factors to try and make that work out. My willingness to research comprehensively things outside of those factors is because my mind is still open, future factors could change, and i'm taking extensive notes on all this in case they do change in the future justifying a different tow setup for other reasons. (there are some job-related opportunities I will be experimenting with that would change me to a different tow vehicle, under the "dual use" principle - I only need to tow on the weekends, and the business can subsidize a van it needs anyways)

[slowmover]

The long term vehicle is the one that can carry you and your family to safety in the event of emergency.

All other considerations are moot.

How fast, how far, how much weight loaded or towing are details of how to specify the vehicle, they are not central.

Basically, one vehicle trumps several, every time . . especially when they are old.

The vehicle that cannot meet this requirement isn't worth owning. Start from there.

.

[larrybuck]

That's why I'm happy w my '85 Suburban. Fuel WILL go up, w diesel more fuel source options.
Suburban easy motel for me.
The near 30mpg. is at a steady 50mph.
It's always ready to tow anything I need.
If I'm in more of a hurry; 22mpg is still probably there.
I've got $1300.00 total into it, reliable, and paid for.
With 4wheel drive(manual hubs) I'm ready for cross country winter trips, at the drop of a hat.

All of these above reasons make me believe I'm having my cake, and eating it too!

[stillsearching]

Originally Posted by slowmover

The long term vehicle is the one that can carry you and your family to safety in the event of emergency.

All other considerations are moot.

How fast, how far, how much weight loaded or towing are details of how to specify the vehicle, they are not central.

Basically, one vehicle trumps several, every time . . especially when they are old.

The vehicle that cannot meet this requirement isn't worth owning. Start from there.

.

One vehicle does not and will not work for my particular situation though. :-/ If I have to drive only one vehicle that will do all jobs and be perfectly reliable that means a brand new Cummins turbodiesel dodge at about $50k. And even brand new vehicles can break down or have unexpected problems.

This strategy is about minimum total cost while doing the jobs that need to be done, and under my conditions two vehicles costs less than one newer do everything vehicle, because i'm not hauling over 3000lbs often enough to have to design my life around it.

Two people are not always doing the same thing. Because of the things that I pick up from craigslist, sometimes on a tight schedule (two people "show up before 6pm!" in opposite directions) being able to send someone else in the other direction in a 2nd vehicle works for me. The household in town will have 3 people and 3 vehicles - one normally takes the bus but will help me if I throw him the keys and say "pick up those windows being thrown out 20 miles from here" while I go to grab something else with the Saturn and trailer. The other friend doesn't want to haul anything in his nicer newer Accord and can't tow. If it were really essential to reliably get somewhere we'd probably jump in his as the newest lowest mileage vehicle.

Under any long term emergency condition i'd rather take two vehicles in a convoy than one anyway. You can always abandon one and hop in the other, vehicles can become disabled by any number of problems outside of just reliability - violent crowds, cutting more than one tire, etc. How did we get on this topic anyway? >_<


I do not have unlimited budgets. I gave all the details to welcome anyones brainstorming about ways to explore my above needs with best fuel efficiency with minimum extra costs put in... although "total lifecycle costs" skew towards a newer low or no mileage vehicle with a half million mile lifespan for something in constant duty, this is intermittent duty. The extra costs of "the best" or even just a 4bt are probably enough the TLC never breaks even. I don't know for a fact I will see enough loads that the extra 2-3mpg will ever matter, the resale of modified vehicles is always a ?? so I don't know I can get it back on the tailend, plus it costs the up front cash to finance this which I may not be able to have.

The Saturn I already have which is paid for and will keep will tow "up to" 1000lbs easily, 2000lbs suggested with a braked trailer (normal chassis limit for rear mount only hitch), or 3500lbs estimated with my CAD engineer friend's special weight distributing hitch and a braked trailer. The 2nd vehicle simply handles everything above that whether I choose 1000lbs or 3500lbs. It lets me fetch parts if I have my Saturn apart and the other roomie isn't home for instance. But in general the Saturn is already very reliable for me despite 200k on it. In the future after I rebuild the engine it will be even better - during that time i'll obviously need a 2nd vehicle anyways til I finish the rebuild because i'm a pretty slow mechanic most of the time. But I also just like the security of tearing into my main vehicle and no matter what unexpected problem I encounter I can just drive the other one immediately. Since i'd do my own mechanic work even on a new one I just plain feel better about having two anyways.


What i'm trying to avoid is having THREE just for me and what are primarily my loads though. :P Having a powerful low ratio pickup would better haul the loads and the job when it gets heavy, but never pay for itself, get horrible mileage unladen for the half of the trip there with an empty trailer, create a parking nightmare or require offsite parking at $100/month at Uhaul, etc.

[slowmover]

Why is "horrible" fuel mileage for one decent vehicle that can do any of the work such a problem? Having more than one is not at all economical, especially low reliability used vehicles. Look at threads by Jacob Aziza and his ol' Ford, for example. That's a money maker.