At what psi can I travel 65-75mph?
This Maxxis pdf has the same table. Using the table(s) above, my ST175/80R13 with 1060lbs load could run at a minimum 35psi with ~4% reserve capacity. Is there a +10lbs rule? I run with +1...
Forum Discussion
Bionic Man wrote:
What I don't understand is that there is obviously a market for a higher speed rated ST tire without adding the additional 10 PSI. Not sure why someone doesn't step up and fill that void.
Just as there may be a market for higher speed rating ST type and trailer application tires. I am sure there is a market for 30 mpg 1-Ton dually pick-ups. I bet someone else can explain why we don't have those vehicles on the market.
Bionic, It is because physics dictates that it is basically the inflation pressure that carries the load and that heat is directly related to component flexing amount (load) and rate (speed) plus the fact that it is heat that causes rubber and other components of a tire to have a limited not infinite life.
OK, Maybe that was a snide comment.
Maybe the problem is that physics and technology get in the way.
With all the complaints about "china-bombs" on RV.Net and other forums there clearly is a market for ST tires that are "Made In USA". The problem is that there apparently are not enough US consumers willing to pay the price.
The fact that it was possible years ago to tow at 75 and not have tire failures may have to do with the significant increase in weight of loaded towables. The physics is that tandem axle trailers place significantly higher internal structural forces on a tire than single axle applications even if the vertical load on the tires does not change. That is just one example of that physics thing getting in the way.
The RV market (consumer) dictates that most buyers shop on price not long term quality. Else why do we have Harbor Freight and Walmart?
