Another towing question

[ipso_facto]

Chas

Right. I heard that Ford F250 PSD only comes with 3.73 (or higher), 4.10 is not an option. The power of diesel, it doesn't need 4.10.

DavidZ71

I thought about sizes for a long time and decided on 30' to 32'. The latter turned out to be the ideal size (for me) and the more I think about it, the more pleased I am with this Airstream find. 34' would be too long, while 29' too short.

I deciced not to compromise with the towing vehicle. Even if I did get a lighter truck, it still wouldn't be a good daily driver. No truck is - it is also the handling, not just MPG. Decided to get something pretty light as a daily driver instead of the truck, as light as possible.
It is clear, in light of everything that has been said, that a big block gasser or diesel is necessary to safely move that kind of weight and that kind of size. I didn't know that originally. With 460 moving 8300 lbs while it is rated for 10,000 so it is beginning to approach its towing limits. It's safer to be somewhat under the towing capacity than over.

[davidz71]

ipso,
I think you have made a wise decision. A friend of mine who hunts with me is fortunate enough to have the love of his life who is raising horses. She has a Chevy 3500 dually with 454 engine she tows horse trailers around with. He pull his 5th wheel and a 24' to the campsite the first of the hunting season and then drives an old S-10 Blazer on the backroads. At the end of the season he drives the dually back and picks up the 24' which may stay at the site for up to 3 months. Of course this is a different scenario than what you posed but works quite well for him. I think your current truck is just the ticket for your situation. Have you made any mods to the engine looking to squeeze that last bit of mileage from her?

[ipso_facto]

davidz71

I think you have made a wise decision. A friend of mine who hunts with me is fortunate enough to have the love of his life who is raising horses. She has a Chevy 3500 dually with 454 engine she tows horse trailers around with.

I knew someone else who pulls horse trailers with big block 454. Must be real popular for that application. Re: this thread, he said 10-11 empty and somewhat less than that pulling.

Have you made any mods to the engine looking to squeeze that last bit of mileage from her?

I don't think that it is the engine exclusively that's responsible for the low MPG. You can vary RPMs with a different tranny, an OD. I can get 12 MPG in it but I have to keep it around 2200 RPMs, which translates to 45-50 MPH. But you are stuck with dispacement forever. (But I find about improvement which can improve MPG, I will implement them)

Secondly, it is the weight. The truck weights 2 tons. No matter what drive train it has, the weight will always prevent you from getting good mileage.

Then aerodynamics.

In car like a 70's Lincoln, this same 460 can get more like 17 mpg due to the vehicle being lighter, more aerodynamic and of course a much higher gear of about 3.

I have a small block V8 (350) which is great and it gets 23 MPG on the highway going 70, full of stuff, offering more power than I need (don't think I ever floored it). With its towing package it would be a great towing vehicle for a small A/S, say 19', something under 5,000 lbs.

So in conclusion, I have decided to eventually install a better tranny with OD, or Gear Vendors or something. I haven't yet found anyone who installed GV overdrive in a similar package but it would be most interesting to see the MPG improvement. Assuming an improvement from 11 to 15MPG, it would take about 100,000 miles for the tranny to pay for itself. Which makes sense only if one plans to keep the truck for 100,000 miles, which I do. The engine has low miles on it, so it is worthwhile.

[femuse]

"the weight will always prevent you from getting good mileage."

I don't think the weight of the vehicle is the culprit here. There must be something else causing this low gas mileage: our van has a curb weight of 5433Lbs, but we still get the same mileage as the pick-ups. And, we haven't noticed much difference in MPG with a full paylod or empty.

On a subject mentioned here earlier:

I have been very bothered by the statement made by "rtaylor537", pulling a 8300Lbs GVWR Excella 30ft, with F150, 5.4L with a 3.55 rear axle.

My gut feeling told me this was not right. So, I did a lot of research on other forums, and the general opinion is 6000Lbs is the absolute SAFE weight, 26' length with such a vehicle. I have gathered a lot of numbers about that, I won't waste more space posting them.
If anybody is considering using the same rig, maybe they should check first one of the many discussions What is the biggest TT I can tow? (somebody jokingly suggests :"according to some sales people....a 65' Airstream")

[ipso_facto]

femuse

I don't think the weight of the vehicle is the culprit here. There must be something else causing this low gas mileage: our van has a curb weight of 5433Lbs, but we still get the same mileage as the pick-ups. And, we haven't noticed much difference in MPG with a full paylod or empty.


Possibly. But I am not aware of anyone in 1 ton truck get more than 12-13 MPG. 12 MPG is in fact most excellent for the 454 or 460. I can get that keeping the RPMs at 2200. But you are only going 50 mph then.

As has been pointed out, the same 3/4 HD truck with the smaller V8 would still get about the same MPG. And a base 3/4 truck would get a slight improvement, probably only 2 MPG. There is just something about trucks that doesn't let them get good MPG.

So in the end, I don't know what else to do with it other than getting some kind of overdrive. If I get 14-15 in it I will be most happy. But I would really like to see a testimony by someone who has done exactly that to exactly same platform (Ford F250 Heavy Duty with 460 and 3 speed tranny). I emailed Gear Vendors but haven't heard from them yet.

Tow ratings are your ABSOLUTE MAX and only take into account one 150-lb drive and no options on the truck.
You'll generally max out at about 1000 lbs UNDER your tow rating.

This is certainly eye-opening information.

[davidz71]

ipso,
Have you investigated the Jacobs Mileage Master or Ultra Team ignition systems yet? I installed the Ultra Team on my '92 Z71 4X4 and noticed an improvement in starting and low end torque. I was already getting 19.5 to 20 mpg on the highway and I did not notice any mpg improvement. This is not the case with others though. You might see what the MH guys have experienced with this system. After my son rolled this truck it was put on a '92 Camaro with 305 and when that was sold, transferred to my son's next ride- a '90 Chevy 4X4 Sport short bed truck. It has been on there for over a year now and has helped this engine which is in dire need of a rebuild. I guess I have had that unit now for 7 yrs. and it has been back once for warranty work on the electronics. I'm considering putting one on my other son's C1500 4.3 litre tuck engine as soon as the Jasper engine people replace it under warranty (bad head with water in the oil).

I'm not saying that it will definately give you at least 1 mpg but some people are experiencing this and more. It is a simple bolt on/plug in unit with new plug wires.

[j54mark]

Didn't I hear that there are several electronic fuel injection systems to replace the carb on these motors? I am assuming that it would be like throtle body injection (although somebody somewhere may well have a complete mulitport fuel injection system, complete with new heads). It would undoubtedly help in city driving, but more importantly give a lot better drivablility - easier starting, better acceleration, etc.

Mark

[ipso_facto]

Ford started putting EFI on this engine in '88. Chevy started using EFI in '89, I think. In any case, I think if it had a carburator, I wouldn't be getting even 10 MPG, like some of these 70's big blocks.

My truck had a new engine put in it in mid-90's and I think it meant new EFI, also. (but not sure).

The nice thing about carburated systems (early 70's), they are arguably easier to fix, being 100% mechanical, no computers.

My first car, a used 70's mopar was religiously getting 13 mpg with a small block V8 and 3-speed tranny. After a new carb. it went all the way to 15. I know it is apples and oranges but I am actually somewhat impressed by this big 460 getting almost 12, with way more displacement and torque, not to mention way more weight and aerodynamic as a brick, and generally lower gears.

[lynnmcmullen]

these responses are full of terms and acronyms i dont know
willing translator?
safe towing
cross country
but vehicle will still be 75% in town, not towing
long distance tow
some posts scare me a little

lynn

[2airishuman]

lynn

so u pull up a 7 year old thread

expect OTHERS to read it...

then explain it 2 u?

keep reading

http://www.airforums.com/forums/f138...sary-4569.html

http://www.airforums.com/forums/f138...ist-28713.html

need more?

there are BOOKS on rv'n basics and complete websites on the basics...

and long explanations of almost every concept here already.

so keep reading...

cheers
2air'

[Hibby]

Ipso Facto

The diesel is certainly a great tow vehicle, but be wary of making the change for mileage improvements. My f250 is a 2010 6.4L PSD and mileage is about 15-16 empty at 70 mph, and about 11-12 when towing our Sport 22, and 9-10 when towing our 7500 lb. boat/trailer.

The older 7.3L PSD had much better mileage as did the 6.0 because of fewer emissions control restrictions.

[Mikethefixit]

Hibby
I know if ya slow down, there is a chance you may get run over in Michigan. But if you bring those R's down to about 16 to 18 hundred which should be about 62 to 65 mph you will find a big change for the better in fuel mileage. I could be wrong but not often.

[Hibby]

Mikethefixit,

You're right about getting run over in Michigan if you're going too slow! I usually tow at 65, which puts us at about 1750 rpms... My towing mileage is at 65, which I should have indicated.

[Mikethefixit]

Hibby
With the mileages you quoted ,I dont think I would be happy at all.One thing you have to consider is that machine is NOT BROKE IN. Takes about 60 k miles to break in most diesels.
Also keep in mind its not a gas job and doesn't respond like one. Be gentle on that throttle partner,push down slowly and watch the fuel mileage go UP.
I get with the 7.3 about 14 city and 20 highway NOT TOWING and about 15 to 17 towing depending on conditions and traffic.
As soon as I fill up I will let you know what kind of mileage I got from Jackson/Meijers to Home on 127 from last weekend.

[Hibby]

Roger,

I hear you... But the numbers are real, and I'm gentle on the gas. Your 7.3 will definitely get MUCH better mileage, simply because it doesn't have the emissions control systems on it that they put on the 6.4L. The DPF is a killer, but it's illegal to remove.