FastEagle
Well-known member
- Joined
- Jan 12, 2010
- Posts
- 647
Larry N. said:I just read 571.120, and it has a lot of stuff relating to how warning label values should be calculated, what manufacturers must do, and so on, but nothing that contradicts the typical advice given on this forum about using the tire manufacturer's recommendations about what pressures to use. And I have to believe that the tire maker has a vested interest in maximizing safety with their tires, especially in today's litigious society.
Trucker regulations? The manufacturer has specific recommendations for each tire type AND size, and I doubt the tire knows whether it is on a truck, bus or RV, nor does it consult regulations before blowing or giving an uncontrollable ride (yes, I've had it happen).
You'll need to elaborate a lot to persuade me otherwise.
So you're saying that in order to be within those regs that I have to allow tires to wear way too much in the center or way too much on the edges, and allow them to throw me out of control on certain road surfaces, and to give me a very harsh ride, even though I'm within the structural and design limitations of the tire?
I can't accept your assertion.
My posts are also laced with established tire industry standards. You will not find anything in tire industry standards that will recommend using less inflation pressures than what has been recommended by the vehicle manufacturer. Tire manufacturer's do not set recommended tire inflation pressures, vehicle manufacturer's do. Tire manufacturers build tires to a set of specifications needed and desired by vehicle manufacturers. They also provide standardized load inflation charts for those tires and they are approved by the tire and rim association (TRA) for use by vehicle manufacturers.
Within 571.120 the vehicle manufacturer is directed to set and display recommended tire inflation pressures for the needs of the vehicle and in compliance with standards set forth in the regulations. If there are deviations such as often used by pick-up owners for towing situations the vehicle owner?s manual will also have recommendations for those loads and inflations.
The tire industry doesn?t give a hoot about inflation pressures vehicle owners use above recommendations and below maximums. If fact, they will slyly hope you practice those procedures, because your actions in those areas will more often than not decrease your tires life expectancy.
IMO RV owners most serious concern should be in the weight and balance of their rig, Truck & trailer or Motor Home & toad. If your unit is not over weight and properly balanced your vehicle?s recommended tire inflation pressures are correct and need to be maintained for every movement and while in storage.
FMCSA tire regulations have no provision for recommended tire inflation pressures. Their concern is to insure the tire is inflated to a value that will carry the load placed on it.
The bottom line for you seems to be the tire manufacturer?s tire knowledge. They know all about selection of materials and building tires to specifications. Vehicle manufacturer?s select tires from a list of tires specifically designed for the average performance of the vehicle they are to be fitted to. Tire manufacturers test tires on a machine at laboratory conditions. Vehicle manufacturers test tires on a vehicle under actual road conditions after the machine test. Tire manufacturers provide the operating parameters for their tires. The vehicle manufacturer is solely responsible for tire selection and fitment to the vehicle. The vehicle owner is responsible to himself/herself for vehicle safety. The TRA provide lists of acceptable replacement tires to the automotive industry. Vehicle manufacturers approve replacements for RV trailers. When an owner steps outside of those ropes they are on their own - so to speak.
Probably the most visible collaboration between tire builder and vehicle builder can be seen each week on TV when NASCAR is testing, practicing, qualifying and racing their cars.
I live about 14 miles from the BMW tire testing facility in Greer, SC. Here is a picture of the layout.
http://www.irv2.com/photopost/showfull.php?photo=30525