How would you go about weighing your truck out if the weight of the tires is not included? Take the tires off? Curb weight includes the tires, full fluids and usually the driver. Yea, even the air in the tires Payload is figured using curb weight........

So I would be including the extra weight of the larger tires in everything you figure out. Especially in GVWR and GCVWR.

 

This is specifically why I use helium instead of air or hydrogen in my tires (spare too). The lifting effect of helium has a substantial increase in payload and is well worth the extra trip to the balloon store!!! Make the truck sound kinda funny though.....

 

Dang....a guy should figure out how much lift 32" tires would generate filled with helium.....gain some payload!!! Wonder if that would fly with the DOT......pardon the pun

 

I went to the Ford Dealership Monday,they had a 2018 on the lot equipped the same as my 2017 both STX Super Crew 4x4 5 1/2 foot beds with Max Tow Package 3.5L Eco Boost and 10 speed autos my payload rating is 1,860 lbs but the 2018 was 1,811 lbs.?

 

 

Great illustration of how many people likely tow unsafely. An engineer who doesn't understand payload or tires.

 

I guess I stated my reply poorly. What I was trying to point out is that you can not decrease your payload by adding heavier tires, nor increase your payload by changing to lighter wheels/tires or up-rated springs, etc.

 

What kind of engineer are they and how long did it take them to unfold their license and/or degree from the Cracker Jack box? jk I work for three Elec. PEs and previously worked for an ME and another EE. The EEs can do power but I wouldn't trust them with much else. It's not their area of expertise. The ME was pretty damn good at things. But he did call me when someone was trying to sell him a 9000lb GVWR travel trailer to tow with his '99 F150 std cab short box...at least it was the 5.4 being force fed by a supercharger (his daily driver was a Lightning). Here I am just a lowly desk jockey that worked up from just drafting to design work.

 

he's an engineer so I started second guessing my self.

I used to get that " I'm an engineer crap" from customers when I was a LaZBoy repairman. They would breath done your neck and try and tell you how smart they where and then to find out they where a computer engineer, give me a break.

 

The 2018's have an upgraded rear frame section to handle the extra tonque weight for the 13xxx tow rating. They also have 4050lb rear axle ratings with the max tow pacakge so maybe extra leafs or something This could be why.

Yes you can decrease your payload with heavier tires. Payload is simply the GVWR - the weight of the truck. GVWR isnt simply the weight the truck can can hold up against gravity, it also defines the weight the truck has to be able to handle, turn and stop. If you put on bigger, heavier tires then your trucks braking and handling performance also gets worse.