A Tires Load Capacity???
#1
08-12-2008, 02:10 AM
A Tires Load Capacity???
OK, so trying to learn a few more basics here! The listed load capacity of a tire and maybe how it compares to its load range (D, E, etc) So my truck weighs 5,500 lbs give or take but now I have a trailer so I want some towing performance from my tire. What's the tounge weight of my trailer?? No idea. Call it 1,000 lbs for arguments sake. Now I understand the D vs E rating and all that, but is the load capacity a number worth looking at, and can I get an idea of a tires performance from that number?? There also seems to be no direct coorelation between the load range and the load capacity??? I've seen D tires with as high a number or even higher number than an E depending on size???
I'm really wanting a Mickey Thompson tire next (you may recall from a previous thread), but all three tires I'm looking at (ATZ, MTA, Baha Claw) all have a D rating (no big deal there, that's what I've been using) but the load capacity on all three of these tires in my size (305/70 16) is 2,910 lbs @ 50 psi. These are the lowest ratings of all the tires I've considered and lower than what I'm currently using. My Grapplers are around 3,500 lbs, as are most of the other considerations I've had are in this neighborhood.
But, the M/T's are among the lightest tires I've compared. The Claws are like 57 lbs compared to 70+ lbs on many others. This alone has to be a huge performance implication.
So I guess my main question is how does this weight rating factor in?? Especially with towing a big concern. I'm trying to find that balance between the tire I want (looks) and the "best", most practical choice, cause you know with tires you can't have your cake and eat it too!!
Thanks guys.
I'm really wanting a Mickey Thompson tire next (you may recall from a previous thread), but all three tires I'm looking at (ATZ, MTA, Baha Claw) all have a D rating (no big deal there, that's what I've been using) but the load capacity on all three of these tires in my size (305/70 16) is 2,910 lbs @ 50 psi. These are the lowest ratings of all the tires I've considered and lower than what I'm currently using. My Grapplers are around 3,500 lbs, as are most of the other considerations I've had are in this neighborhood.
But, the M/T's are among the lightest tires I've compared. The Claws are like 57 lbs compared to 70+ lbs on many others. This alone has to be a huge performance implication.
So I guess my main question is how does this weight rating factor in?? Especially with towing a big concern. I'm trying to find that balance between the tire I want (looks) and the "best", most practical choice, cause you know with tires you can't have your cake and eat it too!!
Thanks guys.
Last edited by Galaxy; 08-12-2008 at 02:13 AM.
#2
08-12-2008, 07:31 AM
Senior Member
In all honesty, a load range C tire with a max capacity of 2400lbs will not be overloaded if you do not overload your vehicle per the GVW/GAW. That 2400 lbs is per tire. Your truck doesn't even com close to a 9,600lb GVW. You would not even need to run the LR C at max on your truck.
The only ones yuo really need to worry about are P-series tires. On a light truck, they are rated at about 90% of what is on the sidewall. That plus too flexible of sidewalls, makes them unsuitable on light trucks in my opinion.
P.S. - Your truck/hitch is not rated to a 1000lb tongue weight. At best it will be 750lb with a WD hitch, 500lb without.
The only ones yuo really need to worry about are P-series tires. On a light truck, they are rated at about 90% of what is on the sidewall. That plus too flexible of sidewalls, makes them unsuitable on light trucks in my opinion.
P.S. - Your truck/hitch is not rated to a 1000lb tongue weight. At best it will be 750lb with a WD hitch, 500lb without.
Last edited by kingfish51; 08-12-2008 at 07:35 AM.
#3
08-12-2008, 04:43 PM
Hey Galaxy,
I don't claim to know any of this either, so take this for what it's worth!!
I'd have to concur with kingfish on the LR C tires... If you pump them up to 50 psi you will have a combined LR that far exceeds any rating the existing truck has...
The LR amounts go up with tire size as you have seen. Even in LR C tires, the 'larger size' the tire is, the higher the LR is. Just as you have seen on your D's and the E's.
Back in the old days, truck tires used to have a 'ply rating', in that a C had '6 plys', a D had '8 plys' and an E had '10 plys'... This is still kinda true today, but it seems to be mostly in the tread now a days, where in the past, it was the sidewalls that had all the plys (I think...)
Sure, a D has a stiffer sidewall then a C and an E is stiffer then a D. Thus, that's why the E's come on the Superduties and other "3/4" ton trucks and the C's and D's are mixed in accordingly.
Do I think you will have a 'safer' or 'better performance' ride on D's or E's then running the same exact load on C's??? I don't know, but I know that when I run my C's at the 50 psi when I'm hauling or towing I have a very stable ride. I don't bother to change the PSI once I'm camped, so I 'sight see' with the tires at 50 psi and don't even really notice much of a handling difference either... It maybe a bit firmer of a ride when it's empty, but not bad at all...
I've forgotten to lower the psi once I've gotten home and run a week or so with them still at 50 psi and when I do lower them to around 40 psi, I can tell that it's a smoother ride for the most part. I can also tell a bit of a different wear pattern on the rear tires for obvious reasons, so I do try to lower the psi for my everyday running around!
Most tires will have a max LR for a specific PSI.. So, if I really only need say #4000 of rear wheel axle load (#2000 per tire), I could probably get by with only the 40 psi, even when loaded up... But, I just like to run 'em at 50, as they seem to run cooler and therefore should stand up better and give me 'less' of a chance of a blow out...
I run my little Goodyear ST175\80\13 trailer tires at 40 psi where the tire says it's max is 35.. Why?? Because when I run them at 35, they get hot enough that I can't keep the top of my hand on the sidewall for very long after a long, hot day haul. I put them at 40 and I can keep my hand there all day, after the same long, hot day haul... I've been doing that for the last 4 years and I've YET to have a blowout on my trailer.... As opposed to the second time I ever towed it and I had a tire go out on me (when they were at the 35 psi)... I never did find out what happened to that tire, but I'm still running the original tires on the trailer and they are doing fine! (yes, I know all about the aging of tires, especially trailer tires, so that's why I'll be getting some new ones by next camping season!
)
Anyway, I think you should just get the tires you want and feel will give you the best looks and weight savings you are looking for. Sure, a D is overkill for an F150 with only a #4000 rear GAWR, but if it makes you sleep better, then go for it! Run 50 psi in 'em and see what the temp is and go from there. That's what I did and it's worked so far!
Good luck!
Mitch
I don't claim to know any of this either, so take this for what it's worth!!
I'd have to concur with kingfish on the LR C tires... If you pump them up to 50 psi you will have a combined LR that far exceeds any rating the existing truck has...
The LR amounts go up with tire size as you have seen. Even in LR C tires, the 'larger size' the tire is, the higher the LR is. Just as you have seen on your D's and the E's.
Back in the old days, truck tires used to have a 'ply rating', in that a C had '6 plys', a D had '8 plys' and an E had '10 plys'... This is still kinda true today, but it seems to be mostly in the tread now a days, where in the past, it was the sidewalls that had all the plys (I think...)
Sure, a D has a stiffer sidewall then a C and an E is stiffer then a D. Thus, that's why the E's come on the Superduties and other "3/4" ton trucks and the C's and D's are mixed in accordingly.
Do I think you will have a 'safer' or 'better performance' ride on D's or E's then running the same exact load on C's??? I don't know, but I know that when I run my C's at the 50 psi when I'm hauling or towing I have a very stable ride. I don't bother to change the PSI once I'm camped, so I 'sight see' with the tires at 50 psi and don't even really notice much of a handling difference either... It maybe a bit firmer of a ride when it's empty, but not bad at all...
I've forgotten to lower the psi once I've gotten home and run a week or so with them still at 50 psi and when I do lower them to around 40 psi, I can tell that it's a smoother ride for the most part. I can also tell a bit of a different wear pattern on the rear tires for obvious reasons, so I do try to lower the psi for my everyday running around!
Most tires will have a max LR for a specific PSI.. So, if I really only need say #4000 of rear wheel axle load (#2000 per tire), I could probably get by with only the 40 psi, even when loaded up... But, I just like to run 'em at 50, as they seem to run cooler and therefore should stand up better and give me 'less' of a chance of a blow out...
I run my little Goodyear ST175\80\13 trailer tires at 40 psi where the tire says it's max is 35.. Why?? Because when I run them at 35, they get hot enough that I can't keep the top of my hand on the sidewall for very long after a long, hot day haul. I put them at 40 and I can keep my hand there all day, after the same long, hot day haul... I've been doing that for the last 4 years and I've YET to have a blowout on my trailer.... As opposed to the second time I ever towed it and I had a tire go out on me (when they were at the 35 psi)... I never did find out what happened to that tire, but I'm still running the original tires on the trailer and they are doing fine! (yes, I know all about the aging of tires, especially trailer tires, so that's why I'll be getting some new ones by next camping season!
)Anyway, I think you should just get the tires you want and feel will give you the best looks and weight savings you are looking for. Sure, a D is overkill for an F150 with only a #4000 rear GAWR, but if it makes you sleep better, then go for it! Run 50 psi in 'em and see what the temp is and go from there. That's what I did and it's worked so far!
Good luck!
Mitch