ragerjr

I know this has been discussed on countless threads but I notice something on the Manufacture Door Sticker the other day on my truck. On the sticker it states that the GAWR for Front and Rear as xxxx#s with XXX tires. So since several people say that these #s are what you have to go by for payload/towing/GVWR.
So with the above said if a person changes something say like put LT tires on the truck like a lot of us do (including myself). How does this effect the GAWR/GVWR/Payload? I have done a lot of research on this just to try and understand how these #s come about. I have come to the conclusion that it is the weakest part of the truck/axel. On my truck the weakest part of the axel (at least from what I can tell now) is my springs. If I change those out then the weakest link will be my wheels because they are rated for 2025 per (according to the 2010 Ford F150 source book). I have a 2010 SC 4x4 with 3.55 rear end (9.75). I have confirmed this from the VIN.
Now I am not saying that by making these changes you will up your payload/GVWR/GAWR but it is food for thought. Any changes that have been made to our trucks outside of what the OEM has put on the truck can change the truck in many ways both good or bad.
With these changes made does it change those #s?
Here is what we know:
If we add weight (ie. toppers, hitches, toolboxes, etc) we take away from our payload of the truck.


I have also seen several people talk about the fact you need to have 3.73 rear end to pull heavy but yet some of the superduties have 3.55 in them and they tow heavy ((diesel)(I understand the difference between gas and diesel)).


So what does everyone else think?

Dirttracker18

Just to touch on your last statement and clarify.

Diesels have a much higher amount of torque and a more flat torque curve with max torque occurring at a very low RPM. Thus they do not require deeper or higher numerical gears to achieve the same torque at the wheels. In addition they have a much lower max RPM and cannot run at highway speeds with deep gears, barring exceptional overdrive.

11screw50

Pretty sure this has been discussed before but yeah, in theory you could keep replacing the lowest rated component and while it would help your truck handle additional load better, it still would not change the sticker. That said, if something were to happen, you might be able to argue about the upgraded parts.

Pretty sure the HD payload trucks do have a different frame though so while you might be able to pick up a couple hundred pounds, you wouldn't be able to get to HD payload

The source book I found for 2015 has a lot of data missing. And all of them that I have seen have had things that made me wonder who put them together.

ragerjr

I agree with you that you will not be able to make it an HD version due to the frames being different. You could though beef it up. You are correct in the fact it does not change the OEM configuration #s on the sticker, but does change the real numbers on the truck either up or down depending on what has been done.


I will also say you are right about the source book because there does seem to be data missing even in the 2010 one.


I am also sure this has been discussed before and I have probably just not found it or forgotten about it. I just thought it was very interesting that the word "with" was below the GAWR #s and nothing that I have read to date has said anything about that in the forum.


Thanks for the thoughts to everyone.

brulaz

In addition to the "WITH" there's also an "AT" after the tire size which gives the rated psi for that size tire and that GVWR. The main purpose of this information is to be sure people don't under-inflate their tires so that they cannot support the truck's GVWR.

But all that goes out the window when you change tire size/type. For example if you go to an LT-E tire of the same size, the tire pressure to support that GVWR is very different.

Or, for example, when you go from F250 to an F350 with the same size/type tire (LT-E), the door sticker for the rear tires will list 65psi for the F250, but 80psi for the F350 to support it's higher GVWR.

However, just inflating the-LT-E tire on an F150 or F250 to 80psi, does not increase their GVWRs.

ragerjr

Brulaz, I agree with what you are saying. But would you also agree that those #s are out the window because you are no longer setup with the original OEM way? If I would take and change out my springs/rear end to the MAX Tow setup then would my truck at that point be a 7700 GVWR truck? Real world yes it would because all of the components would be the same. The frame, wheels, trans, and brakes are already the same. I have the tow package on my truck already so I already have the Aux cooler for the trans. Again this is on a 2010 5.4 4x4. On paper no it will not change anything. This is all just theory.
I am not saying this should be done or that it is legal. Just putting the food for thought out there.

brulaz

What you are suggesting is commonly done.

For example the difference between a recent F250 and F350SRW is only the front and rear suspension and tire pressure. The axles, brakes, engine/tranny cooling are identical. And you can create a mechanically equivalent F350 from a recent F250 by ordering the SnowPlow option (boost front suspension) and the Camper option (boost rear suspension) and increasing the rear tire pressure to 80psi.

Or you can just add air bags to the rear or whatever to get something inbetween.

Where things get more difficult is where components other than the suspension or wheels are involved. For example earlier F250/F350s had different brake systems. The F150 HD Payload trucks have different axles, wheels and frames (in some cases).

But going from a Regular Tow optioned truck to a Max Tow optioned truck should be a relatively simple upgrade. I'm not familiar with what it involves with the 2010 F150 models, but it sounds like you already know what the differences are and are upgrading appropriately.

acadianbob

I'm not so sure about the approach of changing one component. If the manufacturer is doing its job, the various components should be pretty evenly matched or they are wasting weight and resources. I would think that you would have to change virtually all of the main components if you want any meaningful change in payload.

ragerjr

I would agree with you except they do waste weight and resources or at least they did in 2010. Here is why I say that, all the HD (8200# GVWR) Trucks Frame are 8.86 x 2.295 x .150 per rail Section (in) (per the 2010 F150 Sourcebook). (The HD trucks only came in regular cab or super cab version with 8ft beds that year). The crew cab version with 156 in wheel base (6.5ft bed) has the exact same frame specs. Also when it comes to wheels there are only a few that are not rated for 2025 per and those are the HD 7lug (2400 per), SVT Raptor (2229 per), and the Steel Spare (2100 per). It is be noted that the Forged Polished Aluminum with Painted Accents 22x9. does not show a max capacity load per wheel in the sourcebook. The one thing that I have not been able to confirm on at least the 2010 MY is if the splines for the axels are the same. Another poster in the forum stated they where but again have not been able to confirm this information.


The source book I am using is dated August 2009 from esourcebook.dealerconnection.com.

ragerjr

Also I just doubled checked about the frame for MY10 truck w/Tow Package and MY10 Truck w/Max tow and the frames are the same. So the only thing that I can come up with in regards to the differences between 7700# and the 7200# versions is the springs, 3.73 gears, and the upgraded rear bumper. Both have the 9.75 ring gear (at least mine does). I don't believe that 3.73 gears will make a difference in the GVWR, so I would throw that change out. I have not ever figured out what the upgraded rear bumper is, so if anyone knows what that is or does compared to the regular bumper please let us know.