Tire vs Wheel Capacity

[BamaRam]

Looking at Carlisle HD I see ST225/75R15 LRE rated at 2830@10mph.


My Dexstar 17-233 wheels are rated at 2830@80mph.


I'm ignorant about tires and wheels and Google-fu ain't working for me.


Am I going to be okay here? Need to buy tires today.

[busterbrown]

First, trailer tires have a load range based on a specific pressure (PSI), not speed (MPH). There is a speed rating for tires but that is determined by the manufacturer and is mutually exclusive of load range.

Remember, load range is is the amount of weight that a tire can support at a specific pressure, usually a "maximum inflation pressure". The wheels obviously have to support that pressure and weight as well.

If your OEM Dexstar wheels are LRE in size ST225/75r15, an LRE tire from Carlisle (in the same size) with a load range of "E" would be appropriately equivalent. The speed at which the tire is "rated" for may be different per the manufacturer.

[BamaRam]

The tires that came from factory are ST225/75R15 LRDs.

I was looking at the chart below which lead me to think that load rating was based speed. Like I said, I have a lot learning to do.


I know that tire pressure increases with heat. If I cold inflate the tire to 80psi and the hot pressure goes to 95-100, am I beyond wheel capacity?

[sourdough]

Looking at Carlisle HD I see ST225/75R15 LRE rated at 2830@10mph.


My Dexstar 17-233 wheels are rated at 2830@80mph.


I'm ignorant about tires and wheels and Google-fu ain't working for me.


Am I going to be okay here? Need to buy tires today.


Re-look at those numbers. I think the tires (LRE) will be rated 2830 lbs @ 80 psi. The speed rating is completely different. Your wheels should have the weight/psi they will hold. I've not seen a wheel (there may be some) that have the max speed stamped on them. Both items, wheels and tires, are marked for max weight allowed and/or max pressure allowed - those are the 2 items you should primarily be concerned with. Also, when upgrading to the LRE tires have them install steel valve stems then install a TPMS system if you don't have one.:) As a note; when looking at the tires the max pressure allowed for a specific load range will correspond to a separate max weight, ie; 2830 @ 80psi for LRE. Other load range/sizes have their own weight/pressures that can be found on any number of tire sites.

From what you have posted, and my interpretation of the numbers, it looks like you are going to be fine with the wheel/tire combo.

[sourdough]

The tires that came from factory are ST225/75R15 LRDs.

I was looking at the chart below which lead me to think that load rating was based speed. Like I said, I have a lot learning to do.


I know that tire pressure increases with heat. If I cold inflate the tire to 80psi and the hot pressure goes to 95-100, am I beyond wheel capacity?


The tires are made to accommodate heat buildup when running at max psi.

Just looked at the chart. Don't know why they have @10mph on there - it's irrelevant apparently. Most just state max load at XXX pressure. The chart tells you the max load/pressure for each size tire and load range, wheel size etc. along with the speed rating for each tire; in your case, 81 mph. The speed WILL have a bearing on heat buildup in the tire if you exceed the 81 mph, which I hope you don't. Up to that point the chart indicates the LRE tire is good to go as long as you keep the weight below 2830 per tire at 80 psi and the speed below 81 mph. The LREs should give you a comfortable safety margin over the LRD tires that you have. They made a lot of difference on mine - peace of mind being tops.

[Ken / Claudia]

Before I purchased my Carlisle tires about year and half ago I read through their web and thought I read they rate their ST tires at 65 mph. CW has put some of that information on here in the past.
A couple weeks I tested them out as the wife was sleeping, I passed 2 or 3 18 wheelers traveling together. By doing so I floored it and was just below 90 mph went I looked to see my speed. The tires get not blow up. I went back to CC at 65. By the way I do not advise towing at 90 mph. Passing is a little different and still likely against the law. If stopped I would have earned a ticket.

[BamaRam]

Given my inexperience I dont pull over 63mph. That's why I'm getting hammered by trucks.:):rolleyes:

[BamaRam]

I floored it and was just below 90 mph went I looked to see my speed. The tires get not blow up.


LOL. Smoke check good.

[Ken / Claudia]

Sometimes I look for exhaust smoke when pressing pedal to floor but, was busy watching the roadway and trucks that time.

[ctbruce]

The tires that came from factory are ST225/75R15 LRDs.

I was looking at the chart below which lead me to think that load rating was based speed. Like I said, I have a lot learning to do.


I know that tire pressure increases with heat. If I cold inflate the tire to 80psi and the hot pressure goes to 95-100, am I beyond wheel capacity?No. You will be fine. This is designed into the tire if you start at the max cold temp.