I have a 2006 F-250 6.0L, SCSB, 4x4, with 3.73 rear end, air bags, overload springs on BF Goodrich Trail T/A LT265/70R17 Load Range E (3195lbs) tires.

I am looking for a larger buffer zone on the load rating of my tires as I am getting close to the 3200lb. capacity of the tires when pulling my 5th wheel trailer. The trailer runs between 12200-13300 lbs depending on what I am doing. My payloads/pin weights can almost max out the tires if I'm not careful.

I have been looking for tires with a greater load rating but I think I am at the max for 17" tires. I would like to be up around 3600lbs or better just to have a wider buffer zone of comfort.

Anyone have any recommendations on tires with a higher load rating than the 17" tires that I am now using?

Seems I have to bump up to an 18" or 19.5" tire to get a higher load rating.

I like the Toyo M-143's on 19.5 wheels but is that an overkill for my needs?

Thanks for you help,
ChrisO

 

It is my understanding that the load rating is per tire. you are nowhere near maxed out. Even if the weight was just split betweeen the 2 rear tires you are only half way there. But load does get spread to the front tires as well so your actual load per tire is even less.

Please someone correct me if I'm wrong.

 

I also very often carry twice the weight you have stated, especially in the winter and have never had an issue

 

I am often close to and sometimes over 6100-6250lbs on my rear axel. That still gives me room on the rear tires of a 100-200lbs. And that even improves with the other tires picking up some of the load, as you say. But that seems a little close and if I could increase that margin it would be nice to do so as long as it is not too expensive.

But that's why I am asking, am I going overboard or is the margin greater than I am realizing?

C

 

If you have a 15% tongue wt! that's about 2,000 lbs. Add 1/2 the weight of the truck and you have another approx 3,800 lbs, 5,800 total worst case. You can tow approx 6,400 combined so you still have plenty of cushion according to my Calc's.

 

While the E rating stays the same for different sizes of tire the actual weight allowed goes up with larger tires. Check out 285/75-17 or 305/70-17 and you will probably find a tire rated for around 3600 lbs each.

Brian

 

I started running the Nitto Dura Grapplers (highway rib tread) last year and I am very happy with how quiet they are and how they handle my towing chores. Excursion pulling 11k TT with 1400lbs TW.
If your truck with 3.73s is handling your 13,300lb trailer OK with your 31.77" tires then bumping up one inch in tire size shouldn't hurt the tow performance too bad. Duras in a 285/70R17E are 32.79" tall and have a load rating of 3750lbs at 80 PSI, so that's 7500lbs across the rear axle, what is the axle's weight rating? My EX doesn't go off road or see any snow driving so these highway treads are a perfect match for it's use, not sure what your truck normally sees.
Here's the spec sheet for the Duras.
http://www.nittotire.com/Tire/Grappl...agrappler#size

 

I believe you are spot on. I changed my factory tires out a few months ago to BFG Rugged Terrain T/A 275/70R/18 (load range E) on my F350. Told my tire guy the tongue weight of my fiver would be around 3,000 or more. He told me the new tires would be twice what I needed. I have just over 6,000 miles on them, half of which pulling 15,000 pounds of 5th Wheel, and they are wearing good with no issues.

 

The Grapplers sound like what I am looking for except I might go with the Terra for off-road/snow use, instead of the Dura. Its nice to have a choice.
My axel rating is 6100lbs and I will admit I have reached and occasionally exceeded it. That's why I want the extra margin in tires.

Thanks for the help. This will save me a bunch of money too.

 

Get the truck on the scales and quite guessing.

go to your local truck stop that has a cat scale. They will give you steer, drive and total weight.

do it empty and then do it with the trailer. That is about the only way to know where you stand.

For SRW on the side wall multiply by two what ever the max load at 80 psi is.

Changing tires to a different size or manufacture may increase what the tire can carry.

 

your rims are only rated to 3195.

upgrading tires won't help unless you also upgrade rims
http://hillerford.com/resource_libra...f250f350sd.pdf
pg. 49

 

10.5" Ford/Sterling is rated to ~7000#, your F-250 is limited on the load index of the tire. F350s with 17" base rims are derated. SRW F350s with 18" or 20" rims that get load index 126 tires are rated for higher. The axle isn't hurting at 6100#, don't fret mechanical damage at that weight.

DING DING DING! $15 or less for a weight ticket, just GET ONE. I keep the Black Cat app on my cellphone and it finds scales for me when I need them. Super easy, super quick, and the only real answer.

That is ultimately the real upper limit on SRW trucks. 4080# per tire like I have doesn't matter if you crack a rim or shear the lug studs off because you went "good'un'tight" on the nuts.

 

Hiller Ford has some good reading. I found my super duty brochure there. I didn't know about this little gem until you posted up this up in which the 2011 technical guide was added to the PDF folder for my truck. I like have these reference guides.

For the OP, I went with 18 inch Lariat take offs knowing they were speced for weight. The rims according to the book were 3590# max with LT275/70R18 tires at 3640# @ 80 PSI load carrying weight. That is just shy of 7200# to the rims and 7280# for the tires. Which is more than enough capacity if you go by TexasTech's 7000# rating on the rear axle. Knowing this gives me a nice warm and fuzzy feeling inside when I need to grab that heavy load of whatever. I will be testing the drive train in a few weeks when I pour a work pad on the side of the house.

 

Good to hear the axel can handle it. I figured there is a large margin for error in this area but I don't want to make it a habit of going over its rated limits. Nice to get it confirmed.

Yes, I try to get it on the scales on every trip. That's why I know I'm at 6100lbs and more depending on what we are hauling. CAT scales are great. Also, the nice thing about traveling in Oregon, which we do a lot, is you can use their highway scales when they are closed, for free. I am going get the Black CAT app though, that's a good move.

I did not realize the weight limitation on my stock wheels. So clearly, if I'm going to increase the tire, I will need to get better wheels to match. But after looking at the Terra Grapplers in the 285/70R17 I was expecting to mount them on a wider wheel anyways. So I have been looking for higher load rated wheels but did not realize my stock were rated as they are.

Thanks everyone for all the good info.
CO

 

What tires did you go with at that size?
Did you also get a spare in the same size?
If so, do you have any issues mounting the larger spare tire?
I was hoping to stay with a 17" wheel so I would not have to get a spare tire on a larger wheel.

C