As everyone is saying.. it varies...
Ive been driving off road - or should I say off Highway for many years with some utter failures on tire performance along the way. Ive had low speed blowouts (underinflated and traveling too fast) bubbling of tire walls (tire failure due to pressure to high and/or too much load), bad wear and tear from different driving condtions etc...
There is no set and forget... nor is there a "this worked last time... lets do it this time" as conditions change, the load in your vehicle changes as does the type of tire you may be running and even some modifications may have an effect eg. suspension changes.
Its all about the comfort of the ride and how you feel as the vehicle is handling the environment.
Here is something to think about. Tire pressure directly relates to tire temperature. Tire pressure/temperature can adversly effect the tires longevity... I think that if a tire pressure is wrong (to soft) it increases the tire temperature and its this process that sees tires fail at high speed (often thought to be simply a blowout).
I think we all agree too high a tire pressure is not the desired solution, so its all about finding the most comfortable ride combining safety of the car and occupants, tire longevity (proper even wear), optimum fuel economy and then a comfortable ride (successful traction included).
So really its follow the suggestions of varied tire pressure as outlined by others in this thread and then seeing how it works for your rig.
Think of it this way.... a basket ball when pumped up to its recommended pressure will bounce nearly as high as from where you dropped it... whereas, the same ball with 5 - 10 psi less will struggle to bounce far at all.
directly relate that to tires.. the hard tire pressure (off road example) would require more assistance from your shock absorbers and suspension in general to try to keep the tire in contact with the ground reducing traction at high speed ie forest fire trails etc. Reduce the pressure by say 10 psi (or as suggested 30 or so psi) the tire is less likely to want to bounce and will there for give you more traction.. this better traction relates to a more comfortable ride.
Another thought when selecting tire pressure think of this very simple and crude .. yet very effective comparison. A childs birthday baloon.... when it has been inflated to resemble what we all know is a corectly inflated baloon is easily suseptible to bursting.. like poking it with a pen for instance. reduce the size of the baloon so it looks like it is under inflated, use the same pen with the same pressure to try to burst it.. ans see the results. It usually can withstand the same pressure and required significantly more pressure from that pen to burst it..
Relate that to tires... a tire can possibly be damaged or punctures easier if the pressure is too high, reduce that pressure and it can be argued that the same tire in the same situation may not have been punctured.... read carefuly... I said CAN be argued!
Ive escorted many vehicles across deserts on may occasions and was responsible for repairing the punctures that were had each day.... prior to me joining the company that I worked for, it was insisted that for the most part of each trip vehicles ran at 30 psi.. over everything... unless the guide asked for a different pressure. So we had vehicles of every discription traveling high speed dirt road over mainland Australia's interior at 30psi including the bituman legs if there were any short bits.. and the number of punctures reduced significantly. Sadely the puncutres were never iliminated... and at $300 - $500
per tire its not a great outcome in my opinion.
However, there are smarter ways to monitor tires nowadays and I have just installed a "sensatire" tire monitoring unit.
it measures tire pressure about 20 times per minute and tire temperature at the same level. this is done by a sensor that is fitted inside the rim. An audible alarm is heard if the any tire pressure falls or rises (whichever is applicable) outside of the set perrameters. Like wise the same alarm sounds if the temp varies outside the set perameters. There are two settings for driving. One is for highway cruising with its own specific perrameters and the other is for off road.
Simpe device, easy to set up, cheap to buy... I paid less than $150.00 posted free for mine and it cost the same as a strip and fit at your tire dealer to install. If it saves one tire its sooooo worth it!
Now I can SEE if my pressures are right or need adjusting.Now, if the temperature rises ti an unsatisfactory level I either have underinflated tires or I need to slow down to reduce the friction/resistance in rolling... an if I have a slow leak, I can see the tire pressure dropping before it starts to overheat.... being able to stop in a safe spot to inspect, repair or change the tire.
... and even around town its amazing to see the pressure vary depending on the time of day, duration of trip which tire is in sunlight and which has been in shade.. each tire pressure was set at the same time and I get a reading sometimes of more than 4 psi variation across 4 tires!
But.... this is a topic where everyone has an opinon... and I am positive there will be many who will disagree with parts of what I have just written.... but its food for thought.
good thread.....
interested in hearing how other people get along and how they manage to increase tire life whilst ensuring the vehicles ride is as comfortable as possible.
cheer
Alby
The pic is of the head unti of the sensor.... four readouts for four tires. Each read out corresponds to the location of the tire on the truck.
