Posted 2006-10-09 2:13 PM (#499) Subject: tire inflation for truck
Posts: 9
The post last week about the electronic tire inflation monitoring device brought up a question that I have had regarding tire inflation for my truck. I tried to search the topic before I posted this but couldn't come up with the answer. By the way I purchased the inexpensive valve stem covers for my trailer, good idea, and thanks. I will still check the tire pressure independently before a trip.
I have a F-250, 2005, V-10, with a topper, and a two horse trailer with a dressing room, empty weight 3250, with horses at about 1000 pounds each most of the time only one, but sometimes two, and quite a bit of gear. When I got the truck there was about 55 pounds of pressure in each tire. The pressure for the front tires is suppose to be 60 and the back tires 80 pounds. My brother seems to think that 50-55 pounds all around is sufficient. Should I run about 75 pounds of pressure on the back tires when I am hauling? Should I leave that amount of pressure in whether I am hauling or not? I only put about 5,000 miles a year and most of them are towing miles. I want to purchase a small living quarters trailer someday with the total weight of horses, trailer, people and gear at about 12,000 pounds, within the range of that truck. Assuming my tires are still good by then, are the tires that came on the truck sufficient quality for that extra weight or will I need tougher tires? I added the tow package on the truck when I ordered it. I am aware that low inflation and hot weather can cause a blowout, something I don't want to experience while towing if I can help it. Thanks in advance. I have learned so much from all of you on this forum. It is a great web site!
Posted 2006-10-09 6:40 PM (#500 - in reply to #499) Subject: RE: tire inflation for truck
Posts: 727
Location: sc
there are several ways to handle this situation. 1. go with the ford numbers, they "should" know best. 2. go with the max psi on the sidewall of the tire, might cause premature wear of the tire.....if you run empty more than loaded. 3. and probably the best way, go weigh the truck, loaded and empty, then check these numbers against the load/inflation chart for your size tires (often found here, http://www.goodyear.com/truck/pdf/databook/loadInflation.pdf) then do the math for yourself.
as for "50-55" being "sufficient".......maybe, maybe not. either way thats not the way i would run my equipment. i run 60psi all around, all the time in my dmax..........but ive been to the scales and i know it IS sufficient for what i do with MY truck.
Posted 2006-10-09 9:43 PM (#502 - in reply to #499) Subject: RE: tire inflation for truck
Posts: 2621
Get a load/inflation pressure chart - see links to tire manufacturers in other threads where this has been discussed ad nauseum.
Weigh your truck axle by axle, loaded and unloaded, dispose of excess air responsibly.
Do NOT exceed the "maximum cold inflation pressure at maximum load" numbers molded into the sidewalls. Don't set TO those numbers either, since they are for MAXIMUM load and if you're carrying that much you have no extra margin.
COLD inflation is usually defined as a tire that has not been run more than a mile in the previous 3 hours, so that resticts most of us to checking them at home, i.e. buy yourself a decent tire gage (or guage).
{or tyre guage)
Try to avoid the temptation to up-size your tires. The stock size is adequate for the truck's capacity and they typically out rate the axles that they're on anyway. Wider tires {phat} may look cool to a 14 year old, but they DO hydroplane easier.
Kinda odd if Ya think about it;
Low pressure leads to high temperature and results in high enough pressure to blow the tire off the rim... Gee, you'd think it would just warm up, reach the right pressure and stop there (-:
Posted 2006-10-10 9:26 AM (#503 - in reply to #499) Subject: RE: tire inflation for truck
Posts: 1563
Location: North Carolina
...Kinda odd if Ya think about it; Low pressure leads to high temperature and results in high enough pressure to blow the tire off the rim... Gee, you'd think it would just warm up, reach the right pressure and stop there (-:
Reg .. I think the final part of your failure mode is wrong. The low pressure leads to excessive flexing of the tire sidewalls. The flexing heats the rubber and cords. When the temperature of the rubber sidewall gets high enough, the sidewall strength is lost. Then the blow-out happens. The tire internal pressure holding the bead on the rim is also lost, then the bead comes off as the tire remains are flapping down the roadway.
I don't doubt the tire heat increases the air pressure. Just not enough to blow the tire off, before the high temperature destroys the tire.
Posted 2006-10-10 4:12 PM (#504 - in reply to #499) Subject: RE: tire inflation for truck
Posts: 2621
I woz Joshin'
That little (-: thang is an ascii smiley face, laying on it's left ear.
In all seriousness tires DO leave home with low pressure, warm up due to excessive sidewall flexing, then MIGHT get "topped up" 5 miles away at the gas station. What I think sometimes happens is that the owner gets to the gas station and decides they're not too bad afterall - so why put a quarter in the machine ?
Yes, I think it is a self balancing system - as far as pressure ONLY is concerned, but as you say the sidewalls are already weakened.
tire inflation for truck
