I am thinking of going to 20" tires and rims for my truck. I have been following all the posts regarding this subject with great interest. I have figured out that I will need 5.5" of bs.

But now my question revolves around load ratings. I dont do any 4x4ing so I dont need any mud tires ( I am running Toyo open country AT's 285 70 17) After doing some research I want to go to a 305 50 20 size tire, as I dont want to go to any taller of a tire due to gear ratio issues. But I have been finding such a great difference of price in tires.

I pull a 37' 5er with a pin weight of around 2100 lbs. Now the tires I have been looking at have a load rating of 3086lbs, is this sufficient? Is there anything else I should keep in mind?

Thanks in advance and Merry Xmas everyone

Kevin

 

Tires have two ratings Load and Weight. The weight rating you gave is good and is the same as the weight rating for a 235 80 r17 load range E. Then yo have load range. While the weight rating may be the same the Load rating can be different. The load rating is the manufacturers assessment of the tires ability to handle the weight rating. A load range E tire will be able to handle the weight rating for extended periods of time in warmer temperatures. A load range D will be able to carry the weight for a lesser time. A load range C will be for very short term us only. If you were ever in an accident caused by tire failure and your tires failed to match or exceed the load and weight ratings of the tires listed on the drivers door...You would be screwed. Lots run bigger load range D tires with big weight ratings but I don't recommend it. A load range E tire will last longer than a D while towing at the rated weight. The tire pressure rating for maximum weight carrying capacity of load range D is typically 65psi and for E it is 80psi. Hope this helps. I have the toyo open country at's on the front and soon I'll have them on the back. A great tire so far with good traction everywhere. A 265 tocat is way narrower than my cooper st 265's. ks

 

ABC, is right but I run Ds on my truck, 1 cause its a dually and I feel with 4 in the back I am a little safer and 2 cause Es in a decent size are hard to find. If you could find an E in your size thats what I would get but in not I wouldnt stress too much about it, however there is the accident situation mentioned above.

 

load range also deals with sidewall strength, and the ability of the tire not too flex, kind of hard too picture and explain, but with a load range D tire (8 ply)any wobble in your 5ver will cause the sidewall too flex, it is much less apparent on a E rated tire (10 ply).

 

Ok, now some of the tires I have been looking at done have that kind of load rating in their specs. The have stuff like 420 or 120v, stuff like that. Here is an example of what I have been looking at http://cgi.ebay.ca/ws/eBayISAPI.dll?...2592&rd=1&rd=1

Would these work? Or should I just bypass them

Kevin

 

Are those a P-metric tire? If so they may not be up to the task of holding up a 7500 lb truck. I'd definately find out for sure before buying.

 

It says on the sumitomo website that it has a weight rating of 3086lbs. So I am guess you would take that number multiply it by 4 = approx 13k. I could be way out in left field on this..... if that is correct, then you would take your 7500 lb for truck , and 2300 lb hitch weight and get 9800 which would leave you about 3k for passengers etc. Is this right?

Kevin

 

Well, the rear axle will carry more weight than the front, so you need to worry more about overloading the rear tires than the truck as a whole.

 

I figured it wouldnt be as easy as I thought,,, thats why Im here,, to learn,, lol. Do you think though that those tires would work,, sure is a good price.
Keeping in mind that I only haul my 5th wheel 4 or 5 times a year, and usually only once for any real distance


Kevin

 

Yeah, they should work, but they are rated a little more than 100 lbs less than the stock tires (3195 lb).

 

Forgive my ignorance,, is that alot, is it something that I should be concerned with?

Thanks

Kevin

 

anyone else have any thoughts or insights on this?

Kevin

 

kevin,

i wouldnt run anything under stock weight ratings, rear axle weight is 1390 kg's (3058 lbs) with a full tank, add 2300 for hitch weight, and you got 5358 lbs. Now take into accont that every time you go over a bump, the weight transfer changes and could probably see upto 6000-6100 lbs on that rear axle.

Those tires you looking at with the 3086 pound/tire = 6172 lbs. not much room for error my friend!!

 

I believe I read somewhere that the AAM 11.5" rear axle is good for over 10,000 lbs (from AAM) even though Dodge maxes it out around 6300 lbs. That indicates to me that the tires are the limiting factor. So, by going to a lower rated tire you're really cheating yourself out of some GAWR. I would try to find a tire with a higher load rating than the stock 3195 lb. That's what I did, and ended up with a tire good for 3305 lb.

 

But if I dont plan on carrying anything other than my 5th do you think it will work?

Kevin