Community Forums

Clay · 05-18-2009, 10:55 AM

I'm looking for a used vehicle and I'm really confused. Let me start from scratch here and see if I understand this.

1. I need to find out the weight a truck can tow.
If I use the "trailer life tow ratings" published here:
http://www.trailerlife.com/output.cfm?id=42175
Would I look for a vehicle with a "tow limit" of over 10,400 which is the GVWR of my trailer?
2. I need to find out the weight a truck can carry.
To do this I have to subtract the loaded truck weight from the truck GVWR and the remainder needs to be at least 2080, which is the estimated loaded pin weight. (20% of 10,400)

Do I have it right yet?

Carol

RustyJC · 05-18-2009, 11:00 AM

If you'll take the time to read this writeup by iRV2 member Ken Lenger, it will cover the selection of a tow vehicle and RV. There's even a link to an Excel spreadsheet at the bottom that will do the calculations for you.

Rusty

Clay · 05-18-2009, 11:36 AM

I read that. I'm looking for a simple formula so I can determine whether or not I need to look at a vehicle. There are so many used vehicles out there. Some obviously won't work, but with others, I'd like a few simple numbers I can run to determine wheter or not it's worth my time and gas to go out and see it.
If a vehicle fits the simple formula and it looks good, I'll dig into it more deeply.

So are you saying I still don't understand????

RustyJC · 05-18-2009, 11:48 AM

I'm saying the manufacturer's trailer tow ratings are overstated since the trailer tow rating is computed as the truck's GCWR minus its curb weight. The manufacturer uses the curb weight of a base truck (no options or accessories) with only a 150 lb driver (no passengers or cargo) as the curb weight. This artificially low curb weight can overstate the real world trailer towing capacity by over 1,000 lbs. One poster suggested selecting a tow vehicle that has a tow rating of at least 110% of the trailer's GVWR to compensate for this overstatement - that's probably a reasonable approach.

I'm also saying that the manufacturer uses this same artificially low curb weight to calculate the payload rating (what the truck can carry) by subtracting the curb weight of a base truck with 150 lb driver from the truck's GVWR. This leads to an overstated cargo rating.

All of this is explained in Ken Lenger's writeup that I linked in post #2. Using brochure information from the truck and trailer manufacturers is, as Ken explains, exactly how he wound up exceeding the ratings for his truck.

Unless you know the laden curb weight of the truck you're considering - that is, the weight of the truck with all options, accessories, driver, passengers, pets, cargo, full fuel tank(s) just as you'll be heading down the road - then sizing a tow vehicle and trailer isn't a thumbnail calculation. That's why Ken put together a spreadsheet to walk a prospective buyer through the process.

Rusty

Clay · 05-18-2009, 03:48 PM

I had tried using the excel spreadsheet, but was not able to save it with changes - thus having to re-enter all the info everytime I plugged in a vehicle. For some reason, I can now save it with changes, so I think that solves my problem.
I apprecialte y'alls patience with me.

gearman · 05-21-2009, 05:40 AM

This is good that you are trying to pick out a proper tow vehicle and understand GVWR and GCWR. But, don't swet a couple lbs either, if you are, then quit looking at 1 tons and shell out the money and get a MDT.

Every manufacture has so many options that affect the truck you really must know what options were available for each year and for each brand. It gets so overwhelming very fast. And buying used, you dont get to pick the options you want, you may or may not find the truck exactly equip to your liking.

I have never heard of someone test driving a truck to the scale to find out exact curb weight, can be done but a lot of work.

RustyJC · 05-21-2009, 06:30 AM

Quote:

Originally Posted by gearman

I have never heard of someone test driving a truck to the scale to find out exact curb weight, can be done but a lot of work.

If one asks on forums like this or one of the truck forums, chances are that someone has a truck very similar to the one under consideration and will share the weight. Our truck, for instance, is 7680 lbs as it hits the road.

Rusty

TXiceman · 05-21-2009, 06:39 AM

And as anot5her reference point, our crew cab dually diesel (F350) rolls across the scales at a bit over 8000#. I could loose some weight if I'd empty my tool box.

In todays truck market, I would tell the dealer he needed to get a weight slip on the truck.

If yo want a FORD, go over to The Diesel Stop and ask for some base weights.

Ken

Clay · 05-22-2009, 08:07 AM

Thanks for the input. It IS difficult to find just what you need in a used vehicle. I need to be patient - which is not one of my virtues - and wait for the right truck to come along. I keep amassing info and that helps me weed through the ads more quickly.

450Donn · 05-22-2009, 09:10 AM

First of all, used trucks are really not that much less expensive than a new one right now. Unless you are looking at an older used.
When considering trucks, you first need to consider a loads GVWR first and foremost. No one will ever buy or own a trailer of any sort and tow it "dry" As a general rule of thumb, a 1/2 ton truck can pull a TT arould 7000/8000 pounds GVWR. A 3/4 ton truck can handle a TT up to around 10000 and a fiver of up to around the same number GVWR. 1 ton SRW can take maybe 12000 GVWR and a 1 ton dually will handle up to around 14000 GVWR. If you are looking at a fiver, remember that 20% of the GVWR of a fiver will be directly on the truck. So it is very easy to exceed a 3/4 ton trucks GVWR by picking a fiver that is too much for the truck.

gearman · 05-22-2009, 12:46 PM

Quote:

Originally Posted by RustyJC

If one asks on forums like this or one of the truck forums, chances are that someone has a truck very similar to the one under consideration and will share the weight. Our truck, for instance, is 7680 lbs as it hits the road.

Rusty

You are giving clayvd advice to worry about every little lbs., then turn around and say not to worry about curb weight.

That they can just go off what someone says there truck weights

Most used trucks have been modified somehow, which will change curb weight.

Might as well listen to the salesman that a toyota tacoma can haul that 40' teton homes 5th

RustyJC · 05-22-2009, 05:06 PM

You may want to read my post again. All I'm saying is that, short of taking the truck to the scales and weighing it, one can get an idea of a general laden curb weight of a truck by getting weights of comparable trucks. That is often enough to establish a range of weights from which one can tell if a particular configuration of used truck is a candidate for further consideration.

You'll find that I'm about as far away from the "Tacoma can tow a Teton" camp as one can get.

Rusty

TXiceman · 05-23-2009, 07:28 AM

I am along the same lines as Rusty on the towing. If you can't get an exact weight, ask for some weights from the folks on the forums. Some have weighed their trucks and have a pretty close handle on the pounds.

You have to allow for gas engine vs. diesel and 2 wheel drive vs. 4-wheel drive as a 4- wheel drive diesel with the long cab and bed will weigh more than the short bed, short cab gas engine and thus will have a lower towing and payload capacity.

Rusty's truck is a close copy of mine except his a a Dodge and mine is a Ford. The Dodges generally weigh less than a like equipped Ford.

Clay, did you drop by The Diesel Stop and check in with the boys there. Smokey Wren is very knowledgable on the Fords and their towing abilities.

Ken

Clay · 05-23-2009, 09:38 AM

I did go to the diesel stop forum recently, but haven't had much time to read a lot. I am trying to get an OASIS report on a 99 F250 7.3 manuel diesel with 94,000 miles. We just drove it yesterday. Being new to diesels, it's hard to know exactly what we're looking for. It was definately louder than our V10, but I expected that. It made a whinny noise that the lot mechanic said was the turbo. He said we could insulate the noise a little. It was a manuel, and we had a couple shaky starts in first, but I think it due to unfamiliarity to the truck.
Carfax came out clean and it's been in the area since it was new. Would like to see the OASIS. We would definately bring it to a mechanic if we plan to buy. Tempting, but will probably keep looking a bit.