Are Our Tires REALLY that sensitive?

frankdamp wrote:
One of the big mistakes people make is to look at the max pressure molded into the sidewall and then use that as their inflation guide. Way too high and putting you at a much higher risk of a blow-out.

My approach is to buy good quality tires (we got Toyos), weigh the rig so you can figure out the individual axle weights when you're loaded for travelling, then inflate cold tires to the pressure the manufacturers' chart tells you. TPMS will give you a heart attack if you monitor what the pressure is while going 70 on the freeway in Arizona in the summer. Check it only when the rig has been sitting overnight and don't sweat it too much.

It really takes a lot of abuse to blow a tire. I worked in Boeing's landing gear group for a while, and we investigated an in-flight tire burst on a 727. It blew when the airplane was at about 12,000 ft, climbing out of Baltimore (I think). It punched an 18" diameter hole in the wheel-well pressure bulkhead and only a couple of USPS mailbags jamming in the hole prevented a disaster.

It turned out the airplane had taxied two miles with a dragging brake, then accelerated for take-off at close to maximum weight, needing about 150 mph for lift-off. After the gear was retracted, the heat build-up caused the failure, which was actually an explosion of gases that had been released from the tire compounds. The failure of the tire bead suggested an explosion pressure of about 12,000 psi. That's why airlines use nitrogen.

The "abuse" possible with an RV pales into insignificance. IMO, as long as you're within 15% of the pressure your weight calls for, don't sweat it. Being slightly under-inflated, based on a weigh-bridge check, is a lot better than being at the pressure shown on the tire's sidewall.

BTW, even after 47 years in the US, I still have trouble not spelling it "TYRE"! Fortunately spell checker alerts me.

Sorry but "blowouts" or Run Low Sidewall Flex like This are normally the result of air loss. Tires can tolerate much higher inflation than the number on the sidewall. many times the wheel is the weakest link.

TPM is primarily a LOW Pressure warning device. The temperature is too distracting for the average user IMO.

Interesting item on the airplane tire. I note that there was an actual investigation and not the knee-jerk "It was a retread so that's why it failed". Brake heat can also revert or un-vulcanize rummer so it turns into silly putty and the tire structure can then simply unwrap from the beads. Probably the tire did not actually see 12,000 psi as the wheel might have failed at that pressure. When the structure of the tire is compromised all bets are off on what will happen first. If you look at the posts on my blog on "blowouts" you will see examples of melted polyester which is similar to what can happen in Nylon bias airplane tires with too much heat.

Sorry but I do not agree that being 15% low on pressure us worse than running the pressure molded on the tire sidewall.

Tyre is fine by me ;)