New Tires

Bert,
If you can get away with the aluminum rims, do so. As weight will effect braking, as will the overall dial of the tire. So if you can stick to the same diameter, lighter in weight, you shod in the end have better braking, mpg, acceleration etc. Or if you have to go a bit larger in diameter, say no more than an inch, go 5-10 and lighter, braking may not be effected at all.

Marty

Vision and Rickson make 19.5" rims for SRW's. 4500 lb Vision rims cost less and are lug centric aluminum while 5000 lb Rickson rims follow OEM offset and are hub centric steel.

A couple of people have suggested buying 19.5" rims for my truck since you can get commercial grade tires in that size. But, my truck is a SRW. Can you get 19.5" rims in non-dually layout?

Bert

Miles Away wrote:
Before I retired I was a traffic homicide investigator and did accident reconstruction, so I look at this as going beyond just a traffic ticket. You must also consider the civil issues involved if you are in a wreck. If you exceed the manufactures specifications you leave yourself open for civil litigation and a situation where your insurance company may abandon you because your modifications materially changed what they thought they were insuring. Use your best judgement and always act as if you were a prudent uninsured.

But, I am not suggesting that I or anyone overload their trucks. As I mentioned, I am trying to make sure that I stay legal and safe. I feel that tires rated at over 4,000 lb will accomplish both of those goals for my truck. I would much rather put a 3,000 lb load on a 4,000 lb tire than on a 3,000 lb one. Yes, it would be legal for me to put that load on a 3,000 lb tire, but I would not feel comfortable with it, especially when I am in the middle of nowhere.

Bert

JIMNLIN wrote:
Sorry about the topic hijack Bert.
I would think the 19.5" tires with their shorter sidewall profile would have less carcass roll than the sidewalls in a taller/larger profile 17"/18" tire.
However those taller sidewalls can sure ride easier than the 19.5" tires.

I don't consider this to be a hijack of my thread. Yes, I was asking about tires, but it is a fact that if I were to go with a size of tire that is significantly larger in diameter than my stock ones, I could easily get into issues with my brakes. That is an important point to know.

At the same time, the comments about the Ford's do show that the manufacture's ratings are sometimes acrap shoot. The same axle having two very different load ratings tells me that there are more factors involved in determining max load rating than just the axle itself. All parts have to be considered.

To be honest, when I started this thread, I had not considered looking at 19.5" wheels. I may have to rectify that.

Bert

LarryJM wrote:
Your both missing the point, no where did I mention that that sticker was somehow written into a law ... it's about operating a vehicle in a safe manner and operating a vehicle outside the limits contained on that sticker and this safety related requirement that I was addressing is where you run afoul from a legal standpoint as was pointed out in the quote I referenced in my initial post here. Such things as wreckless driving, and a host of other laws could come into play. Anyone who is advocating operating a vehicle beyond what is on that sticker is IMO treading on dangerous ground especially when it comes to civil proceedings because of injuries, etc.

To restate those numbers on that FMVSS sticker legally establish the maximum "SAFE" total weight for that vehicle and operating a vehicle in excess of those numbers is doing so in an "UNSAFE" manner and there is where a host of "LAWS" could be applied to cover this area. As always it's up to the courts to determine ultimately what is or is not legal.

Larry

I don;t think that we are missing the point, Larry. At no time did I suggest that I intend to exceed the load limits of my truck. I am dealing with a bureaucratic issue so it needs a bureaucratic response. If I could find 5,000 lb tires, that is what I would put on my truck. That does not mean that I intend to or suggest that anyone else put a 10,000 lb load on the rear axle of their SRW truck. It just helps to ensure that I don't even get close to the "unsafe" realm by staying very far away from the load limit of my tires.

I actually went through this a few years ago with my 5er. When I bought it, it had 15" tires that were rated for something shy of 2,400 lb. I weighed my 5er and found that I had around 2,000 lb on each tire (it has been a while so I don't remember the exact figures). After blowing 2 tires and destroying parts of my 5er, I changed my wheels to 16" and bought tires with a rating of over 3,000 lb. I have not changed the layout or loading of my 5er, so I still have around 2,000 lb on each tire but I feel that my setup is much safer than it was when I bought it.

That is the same with my truck. Yes, I want tires that are rated at over 4,000 to put on it. No, that does not mean that I want to load it up to over 16,000 lb. I want a comfortable margin of safety between my expected load and the rating of the tire. Plus, since I will be driving over some rough terrain, even at less than the manufacturer's GVWR or GAWR, it is entirely possibly for a tire to experience a load of well over 4,000 lb. Since I will be far from any service facility, I would rather have an over rated tire than a flat one.

Bert

blt2ski wrote:
Bert,

Have not seen you in a bit, you got rid of the chebby?!?!?!?! Look at some 19.5" tires too. You can get a 245-70-19.5, same diam as a 285-75-16 or 285-70-17, an LRG will net you about 5500 IIRC. Have not driven the IHC for a bit, so do not remember what I have on the sidewall. If you need a good traction, look at the Michelin XDE M+S....I can't believe I am recomending michiblows.......oh dear oh me oh my! a low point here.......oh dear oh me oh my.....

Marty

Hi Marty,

I haven't been around in this forum much for the last while. I have poked my nose in once in a while to make sure you were OK, though :D

Yes, I got rid of the Chev. I blew both head gaskets at a little less than 70K miles and got a bit, um, annoyed. A deal came up on a 2010 Dodge Mega Cab DRW and I jumped on it. However, my son thinks Mega Cabs are ugly and my wife thinks DRW trucks look like work trucks so after a few years of abuse, I finally traded my 2010 in on a 2014 Dodge CTD 3500 SRW CC. About a month later, I started looking into the possibility of doing some commercial hauling with my truck. The best layout for such a job? 3500 Mega Cab DRW. Figures, huh? :S

My wife and I also adopted our granddaughter. So, I now have a 21 month old running around our house who will undoubtedly soon add her voice to the criticisms of my choice of truck :R I had forgotten how stinky diapers are :E

Bert

I didn't read the posts that are long winded, I assume they are the weight police but,
Hankook DynaPro ATM 285/75/17 are either 3950lbs or 3750lbs. I can't recall off top of my head. I don't know what your stock size is, but I'm guess 265/75/17. So these are only one size off of that.
I have them on my truck and IMO are the best AT tire on the market. I have about 70k miles on them and will use them yet this winter in the snow. I'm a snowmobiler, so I drive in snow a lot chasing the good stuff.

Just giving you another option. I run them at 70-80psi all the time, without them wearing funny. Some people have complained they are too squirmy. I don't think they are at all.

BertP wrote:

Miles Away wrote:
Bert:
I understand. Be careful that you don't exceed your vehicle GVWR as that is an established (legal) limit and is not changed by different tires, springs, airbags or just about anything else. To keep it legal, stay with what you have, aired up to 80 psi (if that is the max psi for your tires)and you should not have any issues.

That's what I used to think as well, but if you check the laws, you will not find a single instance in the US or Canada where the manufacturer's GVWR is the legal limit for any vehicle. Most jurisdictions state that you can tow or load up your vehicle with anything you want as long as it is "safe". They neglect to define "safe", though. So, that's why I would like to have 4,000 lb tires. I will hit the limit of my truck long before I hit the limit of my tires thus reducing the likelihood that my vehicle will be labeled as being "unsafe".

It is strictly bureaucratic so there is little or no logic to it. But, it is the law.

There is some logic to my madness, though. We tend to look at our tires and think that as long as each tire's capacity is greater than half the load on the axle, then we are good to go. After all, half of the axle's load is on each tire, right? That's true if you are driving on level roads. I am considering using my TV in a more commercial setting that will take me off road. In that case, the load will not be split 50/50 across both tires a lot of the time. So, by having 4,000 lb tires in a setting that would usually call for 3,100 lb tires, you are safer when the load on a given tire jumps to around 4,000 lb due to undulating terrain.

That's my theory anyway :h

Bert

Before I retired I was a traffic homicide investigator and did accident reconstruction, so I look at this as going beyond just a traffic ticket. You must also consider the civil issues involved if you are in a wreck. If you exceed the manufactures specifications you leave yourself open for civil litigation and a situation where your insurance company may abandon you because your modifications materially changed what they thought they were insuring. Use your best judgement and always act as if you were a prudent uninsured.

Vehicle brakes are a function of the trucks or trailers GAWRs.

NHTSA says this about components of the GAWR:
"Gross Axle Weight Rating is the rated load-carrying capacity of an individual axle and wheel assembly. (It represents the load that may be steadily sustained by the components in the system; i.e., tires, rims, hubs, bearing, axles, brakes, suspension, sub frame, etc. with the GAWR limited by the components with the lowest working rating".

Our truck makers design and test their own brake systems, or at least a Dodge chassis engineer says at the Chicago truck show.
The truck then has to pass a "minimum" brake test procedure per the applicable FMVSS at the truck makers GVWR and in proportion to its GAWRs.

Bedlam brings up a good point on the F250 vs F350 SRW brake specs being the same and regardless of GVWR.

Ford even markets a one ton SRW with a 11200 GVWR and a 10000 GVWR in the same 172.4" wheelbase crew cab 6.7 diesel 4x4 same FAWR and RAWR..... and all with the same brake specs per Fords Fleet service specs. Ford has other same cab/truck configurations but with two different GVWRS.

Sorry about the topic hijack Bert.
I would think the 19.5" tires with their shorter sidewall profile would have less carcass roll than the sidewalls in a taller/larger profile 17"/18" tire.
However those taller sidewalls can sure ride easier than the 19.5" tires.