Tire Ratings

[JimK-NY]

There is no doubt about it. Truck campers are heavy and most of us are probably close to the load capacity of our trucks. When it comes to load capacity, the limiting factor is often the tires. I know that is my case and my rear tires are carrying close to the rating. To significantly increase my tire load capacity, I need to spend about $3000 for an upgrade to 19.5 wheels and tires.

Ideally I am sure we would all like to have tires rated at more than twice the load we are going to carry. But what do the ratings really mean? Is a tire safe at the rated capacity? It seems to me that a rating should mean the tire is safe at that load. It should be safe as the tire is used and wears at least halfway. It seems there should be some safety margin built into to the official rating.

I do understand that a rating will never compensate for a damaged tire, or for an underinflated tire, or for an old tire that is starting to dry rot. I also understand that a tire can fail even under the best of circumstances. I have had defective tires from Firestone many years ago.

[d3500ram]

...
With modern tires, there is no cross rotation. ...

I think this is now an old wives tale. Cross rotation is permitted unless tires are uni-directional (a la Corvette or similar performance car)

[JimK-NY]

Yes, I could go to Sears to have my tires rotated. I need to make an appointment several days in advance. Between the drive back and forth and the wait times, it would only take 2-3 hours. Or I could pay my dealer $30 to do it along with other routine service. I believe rotation is supposed to be done roughly every 10k miles. For my cars I average 80-100k on my tires. So if I paid I would need to pay around $240 for rotations. Or I could make 8 visits to Sears and spend 20 hours of my own time waiting. With two cars and a truck, I will be visiting Sears a lot.

With modern tires, there is no cross rotation. Tires are switched between the front and the back positions. So all those rotations mean the tires spend half the time in exactly the same position. How is it this adds to tire life? Why does this work better than keeping a set of tires on the rear for half their life and then rotated to the front for the second half?

[ticki2]

JimK-NY wrote:

ticki2 wrote:

JimK-NY wrote:
I plan to continue to replace the rear tires at about 30k and move them to the front for another 30K at lighter load.

It would be better to rotate your tires on a regular interval as recommended in every owners manual . 🙂

Why? My plan keeps new tires on the back to carry the heavy load of the camper.

I have not rotated tires on any vehicle in 30 years. As far as I am concerned the idea of tire rotation is equivalent to the notion of changing oil every 3K miles. It makes money for the dealer and accomplishes virtually nothing. Any slight benefit is lost by the cost of those tire rotations.

Why

It will extend the life of a set of tires

Every tire manufacturer recommends it

Every vehicle manufacturer recommends it

Most tire retailers will rotate them for free for the life of the tires

[JimK-NY]

I think this is an important consideration and the type of information I am looking for. Is this based on knowledge or opinion? I am concerned about tire age because I had a 4 year old tire that dry rotted when it was stored under the bed of my truck. I am also concerned about tread wear. If I am carrying a load near the maximum rating, do I need to take the tire out of service early or can I run the thread down to the warning marks?

[Grit_dog]

JimK-NY wrote:

ticki2 wrote:

JimK-NY wrote:
I plan to continue to replace the rear tires at about 30k and move them to the front for another 30K at lighter load.

It would be better to rotate your tires on a regular interval as recommended in every owners manual . 🙂

Why? My plan keeps new tires on the back to carry the heavy load of the camper.

I have not rotated tires on any vehicle in 30 years. As far as I am concerned the idea of tire rotation is equivalent to the notion of changing oil every 3K miles. It makes money for the dealer and accomplishes virtually nothing. Any slight benefit is lost by the cost of those tire rotations.

All depends what you want to accomplish by doing this. If you're paying retail for tires and can't rotate them yourself then you should have free rotations anyway or find a new tire shop.
If it makes you feel better to have fresh tires on the back, it's your money, spend it how you like. No harm there. But you'll maximize tire life by rotating the set rather than by born on date.
Fwiw tires don't lose load carrying capacity simply due to age, miles or treadwear.....within reason.

[JimK-NY]

ticki2 wrote:

JimK-NY wrote:
I plan to continue to replace the rear tires at about 30k and move them to the front for another 30K at lighter load.

It would be better to rotate your tires on a regular interval as recommended in every owners manual . 🙂

Why? My plan keeps new tires on the back to carry the heavy load of the camper.

I have not rotated tires on any vehicle in 30 years. As far as I am concerned the idea of tire rotation is equivalent to the notion of changing oil every 3K miles. It makes money for the dealer and accomplishes virtually nothing. Any slight benefit is lost by the cost of those tire rotations.

[ticki2]

JimK-NY wrote:
I plan to continue to replace the rear tires at about 30k and move them to the front for another 30K at lighter load.

It would be better to rotate your tires on a regular interval as recommended in every owners manual . 🙂

[SugarHillCTD]

No grain elevators but CAT scales are around.

CAT Scale map for NYC area

[realter]

Then quit worrying and enjoy that nice camper:B

[JimK-NY]

I have a diesel, but actually that is of little consequence since the weight of the engine is on the front. Your 10K guess is probably light by about 500 pounds, fully loaded. I am carrying about 4900 on the front axle and about 5600 on the rear. My estimates could be off by a few hundred pounds putting me at 6000 at worst. That should still be within my 6400 pound tire load rating.

My concern is not about a few hundred pounds either way but about the meaning of the tire load ratings. So far I have driven my rig over 70k miles. I have had to replace two pairs of tires due to road damage so my existing tires are pretty fresh. I plan to continue to replace the rear tires at about 30k and move them to the front for another 30K at lighter load.

[realter]

JimK-NY wrote:

realter wrote:
Have you found a place to weigh your Igloo? Almost any farmers grain elevator will let you roll over their scale, for free, as long as it's not harvest.

I live on Long Island, NY. I doubt there is a grain elevator within a 1000 miles.

My daughter and sil lived in Queens. I always assumed Long Island was

full of skyscrapers and wall to wall people. Was I surprised to find out there wer open fields and small farms and orchards. Very pretty area. Now Manhatten, that was different. 2 days and I was ready to come back to NE, and NE doesn't stand for Northeast as some of you think.

I looked on North* website, and the Igloo weighs 600 lbs more than mine stripped down. With most options, my TC and truck weigh right around 9,200 lbs. No water, no beer,
and no wife.

I'm guessing yours weighs around 10,000 lbs, no grain elevator needed.

[Grit_dog]

You're not going to find many hard facts about the failures because there aren't that many.
What you'll find about the successes are that many do in fact "overload" the ratings of vehicles daily and can only offer their opinion because there isn't an engineer to stamp the new "rating" to make it a fact.
Youll have to form your own opinion about what you consider to be a "safe" load for your setup.
I grew up kind of like Lambo watching and participating in work activities that would just bury vehicles. In high school I turned wrenches for a landscape nursery and thanks to that experience I learned how to weld frames and replace springs and axles! I saw what the trucks (weaker than new ones today) endured day in day out and I saw what/when they failed.
When a brand new 1 ton 1989 Dually gasser is grossing 40klbs gcvw and it takes the upper limit of that to actually start breaking things, I don't feel too bad with 4000lbs in the bed of my truck occasionally, on OE rims.

[JimK-NY]

Kayteg1 wrote:

JimK-NY wrote:


I live on Long Island, NY. I doubt there is a grain elevator within a 1000 miles.

What did I win?

Nothing!.. I could not find any grain elevators with your google search. The search hit elevator companies and feed stores.

[LamboDesigns]

Kayteg1 wrote:
How often farm truck run at 70 mph for several hours?

A lot of life was close to home but it went to a few cattle sales and it might have gone over 70 a time or two.... for an hour or two:) That truck had a hard life even before we owned it because we bought it as a totaled wreck and rebuilt it.

As a retired engineer that did some stress/environmental testing for weapon systems that went on fighter aircraft I know that a lot of "failures" were due to setup errors (I know... I made some of them) and had the system under test been properly fastened the break would not have happened. One such test cost us tax payers a lot of money as things that had been in service for decades got replaced/scrapped to "prevent failures" even though the vibration levels were bogus, the system was improperly mounted, and I had tons of data to back it up. The powers to be just wanted to be safe because a failure had occurred. That was almost 30 years ago and it still irritates me at the waste of money.

I guess I just find it hard to believe most cast rims of different sizes and designs from ford (only ones I looked at) have the exact same load rating. Like I said though.. the wheels/tires I run now are within their ratings.