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Kiddikop1's avatar
Kiddikop1
Explorer
Jun 30, 2013

Are my calculations wrong?

I think I goofed big time. After reading a lot about the Ecoboost, and having owned a 5th wheel with an F350 in the past, I decided to go with the smaller Ecoboost, and was impressed with the high towing figures. So, I got this nicely tricked-out truck, and much to my dismay, after reading many many posts here and on other forums, I am just worried silly that my truck is not up to snuff. I want desperately to be able to pull a 5ver, knowing the limitations with a short-bed (I had a Pullrite on the F350 and loved it), but it seems like this is not possible with the numbers I’ve computed. So, please help me out by checking my figures, and suggesting any possible solutions.
2013 Ecoboost, short-bed, FX4
3.73, Max Tow Package, 7650 GVR Package
GCWR=17,100
Max Loaded Trailer Weight=11,200
Rear GAWR=4050, Front GAWR=3750

I weighed the truck, loaded with fuel (36 gal), myself and passenger, supplies, but no hitch
Loaded weight of truck came to 6500
Unfortunately this was on a waste management co. scale that did not have a way to get rear axles.

If I add 200lb. to my truck weight (for a 5ver hitch), it comes to 6700. I subtracted that from the GCWR of 17,100 and got 10,400.
But then I subtracted the truck weight from the GVWR and got 950. I then divided that by .18 and got a final reading of 5277 lbs that I can safely tow.

Is this right? If so, it looks like a 5ver is out of the question because I doubt if there are any out there that would come in at that weight and be anything decent.
I pray that I am doing these calculations wrong. Even when I divided the 950 by .15 (for a regular trailer hitch), I still only have 6333 lbs to tow.
Something just seems terribly wrong and unfair to me. Don’t wanna whine because I do have this wonderful new truck, drives like a dream, getting over 17 mph, smooth ride, but I have just retired and was looking forward to getting about a 30 ft. 5ver or trailer and striking out cross-country. If these numbers are right, looks like I’ll have to settle for a hybrid or a pop-up!

Any suggestions would be helpful. And thanks for all the posts. I have been lurking on the forum for years but never felt I had enuf expertise to contribute anything useful. Maybe some day I can pay-back to all you folks who take the time to help those of us who are wandering around in towing la-la land!
  • BenK's avatar
    BenK
    Explorer
    Jul 05, 2013
    Maybe this will help un-confuse you on the numbers, which is really what those
    acronyms are

    • GVWR, Gross Vehicle Weight Rating and applies to both tow vehicle and trailer (fiver or tongued)
    • GAWR, Gross Axle Weight Rating and normally need a suffix of prefix of 'front' and 'rear'
    • GCWR, Gross Combined Weight Rating and is the sum of the tow vehicle weight (which includes EVERYTHING loaded onto and into the TV

      PLUS

      the trailer (fiver or tongued)


    Those ratings are a equal to or less than number



    The rest of it is having actual weights to then use simple math
    to figure out where you are in reference to those ratings (acronyms)

    The performance (mainly at the extreme...like when you need to make
    an emergency maneuver to avoid something) and longevity a bit past
    the OEM's warranty period.

    Performance can also be viewed as the ability for that tow vehicle
    to manhandle that trailer based on the GCWR.

    It's not to say that the wheels will instantly fall off if over those
    ratings, but they will sooner and not perform as the OEM promised you
    via their published specifications
  • Kiddikop1's avatar
    Kiddikop1
    Explorer
    Jul 05, 2013
    Thanks for all the advice. I have not yet even come close on deciding what to buy. Actually I will be going to the Hershey, Pa show this fall and will start getting ideas for floorplans, etc. I also plan to weigh the truck at a better scale that will give me the axle weights. Maybe then I'll be better prepared for the show and the dealers who are going to be telling me I can tow anything. Although I am still somewhat confused on the numbers (seems that there are several different formulas that have been suggested), I believe that I am getting a realistic picture now. In no way do I want to go over the weight allowances. Life is too short to take chances just to gain some room for stuff that I can probably do without anyway. Thanks for all your suggestions. I will probably get back to yall after I get more accurate weights.
    Be safe out there!
  • mkirsch's avatar
    mkirsch
    Nomad II
    Jul 03, 2013
    You can park the truck with one axle on the scale and one off to get a per-axle weight. Just drive on until the front is on the scale, get a weight, then drive off the other side until the rear is on the scale, and get a weight.

    There is no realistic way to tow even the smallest 5th wheel with this truck and stay within GVWR. The best you can hope for is to not exceed the individual axle ratings.
  • BenK's avatar
    BenK
    Explorer
    Jul 03, 2013
    BurbMan wrote:
    If you add back in the 200 lbs for the 5er hitch, that leaves you with 1150 available payload, plenty to handle the tongue weight of just about any 30' travel trailer. 5ers usually put 20% on the pin and TTs put 12-13% on the tongue, so would likely be able to tow a bigger TT than a 5er.

    As Jimlin pointed out you can likely stretch that with higher-rated tires and possibly air bags or Timbrens on the rear.

    To answer your question, your numbers look right, and good thing you are doing the math now rather than after the RV salesman sells you that big honkin' trailer.....

    You'll be able to get a nice rig that's bigger than a hybrid or pop-up, you just need to keep a close eye on the numbers.

    On a final note, pay attention to the loaded weight of any trailer. On average you will add 1000-1500 lbs of stuff to either a 5er or TT, so be sure to add that to the dry weight of whatever trailer you are looking at. Most of the 5er's storage is in the basement up front, so a lot of that goes right to pin weight.


    Ditto, but wonder if the OP is only looking for confirmation of what
    he wants to buy...

    Repeat the best is go out and actually weigh his TV axle by axle instead
    of guess what his loaded weight will be

    That is the only way to know where 'that' TV is in reference to it's
    ratings

    Then the basis for figuring out what the true MTWR for a Fiver or Tongued
    will be
  • myredracer's avatar
    myredracer
    Explorer II
    Jul 02, 2013
    Don't believe any of the highly inflated towability numbers the various manufacturers are flogging these days. It's almost scary what they are doing. The "1/2 ton towable" label has been around for a while and now I see that KZ is using a "1500" and "2500" designation on their trailers for 1/2 and 3/4 ton tow vehicles.

    KZ is now listing a 34' Durango 5th wheel with a dry weight of over 8,000 lbs as being suitable for a 1/2 ton. I'd like to now how any 1/2 ton truck can handle that, even with a HD tow package. Am I missing something? Our 3/4 ton truck would not even be able to handle this trailer on the basis of payload. I also see that KZ seems to have lowered the 12K+ GVWR for this (or similar 34' model they have) to 10,800 lbs GVWR. I am guessing that this is to make it appear more tow-able by a 1/2 ton? I am pretty certain if this is the case, the loaded weight of the trailer will be pretty close to the 10.8K GVWR and not leave room for a tank of fresh water even (happened on our current trailer). And what about the RAWR with this trailer on a 1/2 ton?? They, as are most (or all??) are silent on payload and RAWR limits and calculations.....

    The trailer manufacturers are all playing a weight numbers game and regretfully you have to go onto forums to educate yourself.
  • ependydad's avatar
    ependydad
    Explorer
    Jul 02, 2013
    skipnchar wrote:
    In order to tow a 5th wheel of any size you need to have ordered your truck with the HD Payload option (8200 lb. payload). YOu can still tow a 5th wheel but it will just need to be a smaller one than otherwise would be possible. Payload is the main thing to look at for 5th wheel towing regardless of WHAT size truck you are using. People are quick to point this out with half ton trucks but it is just as much a factor with 3/4 ton trucks but many just ignore it in that case.
    Good luck / Skip


    I find myself commonly agreeing with Skip. 1/2 tons just don't have the payload needed to tow much *if* you're going to adhere to all ratings.

    The fact that you wanted rear axle weights already says that you're willing to overload the GVWR and limit yourself to rear axle + tire load capacity. A lot of people do it. Not my way, though.
  • BurbMan's avatar
    BurbMan
    Explorer II
    Jul 02, 2013
    If you add back in the 200 lbs for the 5er hitch, that leaves you with 1150 available payload, plenty to handle the tongue weight of just about any 30' travel trailer. 5ers usually put 20% on the pin and TTs put 12-13% on the tongue, so would likely be able to tow a bigger TT than a 5er.

    As Jimlin pointed out you can likely stretch that with higher-rated tires and possibly air bags or Timbrens on the rear.

    To answer your question, your numbers look right, and good thing you are doing the math now rather than after the RV salesman sells you that big honkin' trailer.....

    You'll be able to get a nice rig that's bigger than a hybrid or pop-up, you just need to keep a close eye on the numbers.

    On a final note, pay attention to the loaded weight of any trailer. On average you will add 1000-1500 lbs of stuff to either a 5er or TT, so be sure to add that to the dry weight of whatever trailer you are looking at. Most of the 5er's storage is in the basement up front, so a lot of that goes right to pin weight.
  • JIMNLIN's avatar
    JIMNLIN
    Explorer III
    Jul 02, 2013
    Your F150 came with the 7650 GVWR and small 4050 RAWR/p tires which will limit how much load the trucks axles can carry.

    The F150 HD package has a 8200 GVWR with larger 4800 RAWR/E tires and wheels for carrying another 700-800 lbs of pin weigh.

    Your F150 rear axle may weight 2500 lb when empty which leaves the truck with a 1550 lb payload (4050 RAWR minus 2500 lbs = 1550 lbs). Actual numbers depend on actual scaled weights.

    I would look at 5th wheel trailers with a 900-1100 lb dry pin weights.
  • BenK's avatar
    BenK
    Explorer
    Jul 01, 2013
    Below is my diagram showing how the specifications/limits/ratings system works

    Best to weigh your setup axle by axle fully loaded ready to go. If you don't
    have one or the other, then use their GVWR's as the potential max...if you load
    everything like most do...few are truly light in the stuff they load

    Also, decide if you believe in the ratings or not.

    If not, then do whatever but a new 2013, assume still under warranty. so know
    that if they find out over loaded, warranty might be denied (I would if I was
    the OEM)

    If yes, then check out the below diagram, gather the specifications for 'your'
    TV and plug in the actual weights to do the simple math.

    You have found out that it is not all about go, but the ratings are the true
    measure. You will get tons of 'sure you can', etc, etc advice, but there is only
    one person responsible for the setup and that is the driver, who might not be
    the OP, but a buddy or spouse. Then the OP should ask themselves if the advisers
    would pay for any overload break down?

    I do not advise with the 'your are good for it', 'sure you can', 'no you can not'
    but provide the metrics for the OP's to figure it out themselves...I have to
    sleep at nite as I take providing advice seriously...

    This is NOT a half ton can't tow anything...everything can tow
    and then they also have specifications/limits/ratings on what they
    are 'rated' to tow.

    Just that half tons have lower ratings and head room than bigger trucks

    Then note that there is a huge spread on 'half tons'. From less than
    6.2K GVWR to over 8.1K GVWR (I call them fake half tons). So many
    get bit by hearing/reading of a 'half ton' doing whatever but miss
    or the poster didn't say they have one of those fake half tons. I've
    gotten several PMs about that and one guy so mad he wanted to sue the
    guy telling everyone a half ton can, but he had one of those fake
    half tons...so this guy who PM'd me burned up his diff towing what
    he though all half ton's can because one guy said he does and advise
    that guy he too could...





    another thread titled: New guy needs help

    BenK wrote:
    Welcome to the forum !

    First decide if you believe in the OEM specifications/limits/ratings or not

    If not, then do whatever but note that if there is warranty left...the
    OEM may be denied. If no warranty, then you have taken the OEM off the
    liability hook

    If yes, then read up and ask lots of questions

    There is a huge difference in how a question is asked or answered
    'Can do' is way different from 'should do' or 'rated for'



    The specifications, limits and ratings is a 'system' and most take
    a single rating as an absolute or out of context....like your reference
    to your TV's MTWR (Max Tow Weight Rating)

    Meaning that, those MTWR's are only a true rating within the fine
    print of the OEM's specifications

    Meaning that they derived those MTWR's from a 'curb' weight TV, which
    is the 'stripper' model with no options other than the tow option
    and one 150lb driver. Some full fluids, others partially filled

    Best is to weigh your TV's fully loaded...axle by axle. That is the
    only way to figure out your 'true' MTWR

    You should gather these ratings for both your TV's

    GVWR
    FGAWR
    RGAWR
    GCWR

    Then do the simple math to figure out your true MTWR

    Some come here looking for confirmation of what they want to hear
    or what they have already decided on....they WILL get many advisers
    that will do exactly that...just ask yourself if those advisers will
    provide the funds for warranty or whatever cost an overloaded TV
    might suffer

    This image shows how the ratings system looks like in graphical form

    howmuchcanitow
  • goducks10's avatar
    goducks10
    Explorer
    Jul 01, 2013
    Try one of these http://www.forestriverinc.com/FifthWheels/Flagstaff/default.aspx?page=floorplandetails&floorplanid=3014. You will have to be diligent in packing. IMO you would be better served with a TT. From my past experience when I had a 10 F150 Maxtow with the 7650 GVW and 1857 CCC, I could never make the numbers work when 5'er shopping. I know what we pack and it's around 1200+lbs. Adding that to the dry sticker weights (not brochure weights) and using 20% as a starting point on the pin I was always right at or slightly over the RAWR and GVW. There are guys on here and also on the F150 Forum that tow 5'ers with 1/2 tons. I find that some are over weight and others are close. I prefer to not be at the ragged edge and to have a sizable weight cushion which allows me to be able to take what I want camping. There's nothing worse than being maxed out.

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