Quote:
Originally Posted by Just Cruisin
My question/response is for anyone to answer but also hoping 'hossross' will respond. I retired after 30 years of quality assurance for aircraft tires. I realize they are different from ground tires but I've never understood why people go by what the RV says instead of the tire.
We had a huge portion of our workforce in development and quality control to make the tires both consistent and to a certain standard. It seems to me that the best people to know what the tires is designed for is the tire manufacturer.
In the 1990s there was the Firestone incident in which Ford and Firestone agreed the tires should be run underinflated to make the ride comfortable,etc. But over 750 people died (I believe that's the correct number) from blowouts.
In the case of Mike Burns question, I wonder what the tires were made for? It's a 2003 RV so what if the first owner put tires on that aren't designed for a chassis exactly like his. What if they are cheap tires or have dry rot from age? It scares me to think that tires that might already be weakened could then be over or underinflated for comfort's sake. Underinflation, which was the problem with the Ford/Firestone issue puts more pressure on the tire's sidewall. Overinflation doesn't keep as much tire on the road.
I hope this didn't come across as arrogant or argumentative. I have often heard people say to go by the RV rather than the tire. This is just the first time I've asked why and I wanted to present my case. I specifically mentioned 'hossross' because he mentioned he was in automotive development and thought he might shed light from the automotive side of things.
Thanks for answers in advance.
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In most cases like all the RV applications, they don't buy enough tires to warrant the tire mfg to design a specific tire for the application so that is why you don't use the tire pressure on the side wall as the authority. Some vehicles sell enough that the tire mfg will provide a specific design tire but that number is probably over a million tires.
Now for the mystery part, Ford Explorer accidents. My short answer is Ford had better lawyers than Firestone. Ford had a handling stability problem in the design, they chose to minimized it by lowering air pressures to 26 psi on the rear tires, When tires loose pressure it goes lower from the starting point, so now some Explores had tire heating and deteriation problems. The rest is a bunch of cascading failures from there, read the wikipedia article for some more details. What I never saw an good engineering answer to was why did many of the vehicles that rolled over have a flat LR tire. in all cases the LR was lower pressure after the accident than the other 3 tires as I understand it. So why does 1 out of 4 tires consistently loose air more than the other 3 over thousnds of vehicles? The result was to trip the vehicle and killed a lot of passengers, Firestone went bankrupt