Mfg. Tow Ratings, How Important?

[FMWeaver]

Let's use my truck as an example in the formulas:



GVWR = 10,500 lbs



GCWR = 21,500 lbs



LCW = 7,680 lbs



GCWR (21,500 lbs) minus LCW (7,680 lbs) = 13,820 lbs maximum loaded trailer weight



GVWR (10,500 lbs) minus LCW (7,680 lbs) = 2,820 lbs maximum hitch/pin weight of loaded trailer

Rusty [/B][/QUOTE]



Rusty,

Here are my results assuming a loaded trailer weight of 17000 ( 16 k empty trailer with 1000 lbs worth of junk loaded. The 1000 lbs is a conservative estimate just to get an approx. number. )

and a LCW of 8000 (7375 lbs curb weight plus passengers, diesel, and other assorted junk)

GVWR = 12000

GCWR = 25000



25000 - 8000 = 17000 Max trailer weight

12000 - 8000 = 4000 Max pin weight



I like your figures much better than the websites!!! Thanks for your help.

 

[RustyJC]

The only thing I question in your calculations is your 25,000 lb GCWR. I think the GCWR for your truck with the 4. 10's is probably 23,000 lbs. If so, your maximum loaded trailer weight (using your numbers) would be:



23,000 GCWR minus 8,000 lbs LCW = 15,000 lbs maximum loaded trailer weight.



In this example, a 17,000 lb trailer would put you 2,000 lbs over your GCWR (gross combined weight rating).



Rusty

 

[Eric_77]

Well you are clicking on SO truck so the GCVW is only 20,000 pounds. so 12,400 is correct for what you typed for a HO engine GCVW is 23,000 and towing is 15,500



Do you have an SO or HO engine?

 

[FMWeaver]

I came up with the GCWR by combining the LCW (8k) and the approx. loaded weight of the 5th wheel I'd like to tow (17k). Adding 17 + 8 = 25k. I realize this is not the GCWR stated on the web site, which is 20k as Eric mentioned. Using the numbers on the web site and Rusty's formula of GCWR - LCR = Max Trailer wt.



20k - 8k = 12k which brings me back to where I started.



Eric, how did you figure 15k for my SO?



Rusty, two of your posts seem to disagree with each other... in your original post you mentioned that one of your old trucks was rated at 16k and that mine ought to be more than that but in a later post you figured my truck at 15k...



this is getting harder and harder for me to wrap my brain around!

 

[RustyJC]

Sorry for the confusion. I was mixing manufacturer's towing ratings (the 16,100 lbs I mentioned) with real world calculations using what I thought were your actual ratings (23,000 lbs GCWR) and curb weight (8,000 lbs LCW) which produced the 15,000 lbs maximum loaded trailer weight.



If your GCWR with the SO engine is indeed only 20,000 lbs as you state, then 20,000 lbs GCWR - 8,000 lbs LCW does give you a maximum loaded trailer weight of only 12,000 lbs if you're going to stay within the manufacturer's GCWR! Sorry for the bad news!



(As an aside, knowing the weights of our 5th wheel, we ordered our truck to get the maximum possible GCWR in the 2002 model year - 21,500 lbs - and the lowest LCW - 2WD dually - so that we could stay within the GCWR and GVWR ratings. )



Rusty

 

[Eric_77]

Originally posted by FMWeaver

20k - 8k = 12k which brings me back to where I started.



Eric, how did you figure 15k for my SO?

I didn't come up with 15k for the SO. same truck HO is 15,500, with SO it is only 12,400.



a HO engine GCVW is 23,000 and towing is 15,500

 

[FMWeaver]

Guess it might be time to start looking at 04&1/2 600's... these ought to be good for at least another six months until the 05's come out (lol). Thanks for all your help Rusty. I notice you reside in the country of Texas , I'm a Texas native myself (San Antonio) but have been transplanted since '89.

 

[FMWeaver]

Originally posted by Eric_77

I didn't come up with 15k for the SO. same truck HO is 15,500, with SO it is only 12,400.



My bad, sorry about that Eric. It was hard to read your post through my tears of grief :{ .

 

[FParisi]

If the tow rating goes up with the HO then if you increased HP with a box that would increase the amount you could tow.

I know it wouldn't increase the tow numbers published but it would increase the amount you could reasonably pull.

Frank

 

[RustyJC]

Originally posted by FParisi

If the tow rating goes up with the HO then if you increased HP with a box that would increase the amount you could tow.

I know it wouldn't increase the tow numbers published but it would increase the amount you could reasonably pull.

Frank

It's not quite that simple. I believe the HO came with the 48RE automatic. The SO had the 47RE. If so, it's a little more than just BHP. If BHP were the only determinant of GCWR, how much do you think mine should be increased from its factory 21,500 lb now that I've increased power from 245 BHP/505 lb-ft at the flywheel to 347 BHP/762 lb-ft at the rear wheels?



Rusty

 

[YOOPERVIC]

Hey klenger, are the towing figs for the '05's about the same as the '04's?

Really appreciate all the info you give.



Vic

 

[klenger]

I have not seen a copy of the 2005 towing guide. If someone can get me a copy, I will post it on my website.