ST235/80R16 Tire Replacement
I wish to go to the LT tires, and the shop I called said they do not make them in that size, I would have to go to an LT235/85R16 tire. He said since this tire is a bit larger than the old, you have ...
Forum Discussion
CapriRacer wrote:
the tires should have MORE capacity than the GAWR.
I recommend 15% more.
Barry being a retired tire engineer, I have a question for you.
The ST tires get a more intense load rating based mostly on the speed restriction of 65 MPH imposed on them.
If one has a LT tire like the OP is talking about such as the LT235/85R16E which carries the industry standard 3042 point rating, with a speed rating of 99 or 106 MPH. If this tire was given a speed restriction to 65 MPH, what could that do to its available load rating.
I will note that companies like Michelin who promotes their XPS RIB for RV use, places a 75 MPH recommended speed on it, I believe they put this speed restriction on it because they know that this application will mostly likely result is a tire being used at or near its max rating.
What I am driving at is when a person chooses a LT tire with a much higher speed rating than any sane person would tow a RV trailer at, have they not included a pretty good buffer regarding capacity to handle their load.
Michelin tire engineers have also told people with their 225/75R17.5 tires with 100KM (62 MPH)speed rating and rated to 4805 pounds that they can drive faster if they decrease the max weight rating. Given that these tires at being used on 7 and 8K axles, there is lots of room to slide the figures around.
If this Speed(^) = Weight(v) applies,
then shouldn't Speed(v) = Weight(^) similar to how a ST tires is rated also apply to other tires. I have seen industry charts of some commercial tires that handle much high weight at low speeds.
Chris
