This could be a stupid question but here goes:

I have a 2013 F150 crewcab Ecoboost. Max vehicle weight of 7200lbs. My issue is going on vacation with a new boat. Boat is going to have 500lbs on the hitch and that is cutting into my payload. Truck also weights more then I thought is did. Took it to the scales and with me (175) and full fuel its just over 6200lbs. So with 2 more people and a dog, well not much left.

My questions is: I have KO2 tires which I know are heavy. Limiting factor here is the axles. So technically the axles are not carrying the weight of the tires so can I safely subtract them out?

 

Nope, that 7,200 lbs includes both sprung and unsprung weight. Not that heavy tires make that much of a difference...maybe 5-10 lbs per tire if they're substantially heavier than stock.

I wouldn't worry much about it though. My '13 had a GVWR of 7,650 lbs, and had the exact same brakes, bearings, wheels, and tires as yours. About the only difference would have been slightly heavier rear springs. Your truck isn't going to care if you go a couple hundred pounds over GVWR.

 

I'd just make sure the tires are aired up good and just take it easy (slow down) and not worry about it. I've seen well I'm sure we've all seen some ridiculous towing setups on the road your truck is plenty capable.

 

I agree with Tom 100%


here's what I've noticed by comparing door stickers:
my 2010 XL 4x2 has a GVWR of 7,000 lbs (give or take) and a payload of 1,700 lbs (give or take).


my coworker's 2013 XL 4x4 has a GVWR of 7,300 lbs and a payload of 1,700 lbs (give or take).


both are super cab short box pickups and wear the same P235/75r17 tires rated at a max of 2205 lbs at max pressure. so what's the difference? why is his GVWR 300 lbs higher than mine? the answer is astonishingly simple ... Ford wants to have 1700 lbs of payload, regardless of configuration and adjusts the GVWR accordingly.


while the GVWR is "the law" it is also disgustingly arbitrary.


furthermore, everything is the same on the trucks with a GVWR of 8,200 lbs. the axles are the same, bearings, brakes everything, except shocks, springs and wheels (and obviously tires). the only thing that needs to be replaced to safely handle a GVW of 8,200 is the wheels and tires.


I would have no problems what-so-ever putting my rear axle up to 4410 lbs, which is the rated maximum of the tires. everything else has a higher rating, so the tires are your limiting factor.


even stopping short of the max tire rating, I would have no problems loading up my truck to the 7,300 lbs listed as the GVWR for the 4x4 scab, vs the 7,000 lbs for the 4x2 scab.


the problem with rating the truck as such is that if my truck had a 7,300 lbs GVWR, then it's payload would be north of 2,000 lbs ... which would really put the hurt on the 2,100 lbs payload listed for the HD payload package .... let alone upsizing to a 265/275 series tire and running up to the 7,650 lbs for the max tow vehicles. that would give me 2,350 lbs of payload capacity, which starts putting the hurt on the super duty's territory.


stay under you tire ratings at max pressure, run your tires up to the max pressure, and you'll be fine. IMO, YMMV, and don't do it just because some knuckle-head on the internet told you to