If my load range E tires have a Max PSI of 80 what PSI should I use for every day hauling? Two horse trailer and I only haul one horse.
Clarification - The question relates to the trailer tires.
Higher PSI means better mileage and better tire wear (less side wall flex, etc.). But it also means a stiffer ride.
We recently returned from a 2000 mile round trip to OK. I ran 80 psi the whole way without issues. Mileage (Chevy Duramax, 3500HD, 4WD, Crew cab, AL flatbed; 4H Featherlight gooseneck with a weekender LQ, 7100 lb. empty; 2 horses and all the gear needed for a full 10 days) ran just under 11 mpg cruising at 65 mph. Because we were reasonably heavy the ride was just fine. Because I’m a cheapskate I won’t de-air to get a softer ride. 
Also, more PSI is better in our wet climate (reduces the risk of hydroplaning).
You can run in the 60 psi range without issue, AFAIK. You might want to check with your local tire shop and see what they have to say.
G.
What is your trailer labeled? The required PSI for my trailer tires is on the sticker that is right behind the tongue.
I adjust pressure according to tire wear. Start at max and if the tire wears more in the center, back off until it’s okay. If you start with less, and the tire wears on the outside more, you don’t have enough pressure. The last two sets of Michei tires I’ve had on the D/A dually lasted for 115,000 miles. I pull all sorts of things but don’t vary pressure. My back tires run at 70, and front at 80 since they wear first on the outsides anyway. Longevity comes from rotation with six in the mix.
FWIW-
I contacted my tire manufacturer after my local tire company told me to underinflate my tires by 30lbs! That was obviously stupid, so I emailed the manufacturer. They said to always inflate them to the max.
I have different plans for longevity than the manufacturers.
[QUOTE=Tom King;8352394]
I have different plans for longevity than the manufacturers.[/QUOTE]
Exactly!
I just learned the hard way about tire pressure. I noticed the middle wearing down on the rears of my truck. It seems I’ve been driving them overinflated as I’ve been using the truck empty or for short/light hauls but running the tires at full pressure. Won’t make that mistake again.
[QUOTE=Tom King;8352394]
I have different plans for longevity than the manufacturers.[/QUOTE]
Indeed!!!
You bring up rotation. On dually that’s a critical item. I do it every 7500 miles or so and do the six tire rotation. Is there any reason to include (or reason not to include) the spare?
G.
I don’t keep up with the mileage, but I doubt I rotate any more frequently than 20 or 30 k. The fronts wear on the outside fastest of any, but still not THAT fast. When I see the little grooves on the outside lugs wearing down, they get switched to the back, and a back pair moved up front. The back four wear pretty evenly. I might do three or four rotations before they are worn enough to serve on a utility trailer, but not completely worn out.
I never think about the spare.
and they still need replacing every five years if trailer kept uot in the sun.
We don’t put enough miles on our trailer to wear out the tyres, but replace them anyway.
[QUOTE=Tom King;8352136]
I adjust pressure according to tire wear. Start at max and if the tire wears more in the center, back off until it’s okay. If you start with less, and the tire wears on the outside more, you don’t have enough pressure. The last two sets of Michei tires I’ve had on the D/A dually lasted for 115,000 miles. I pull all sorts of things but don’t vary pressure. My back tires run at 70, and front at 80 since they wear first on the outsides anyway. Longevity comes from rotation with six in the mix.[/QUOTE]
Thanks for that. That was something I hadn’t even thought of.
… is this 80 PSI when the tire is cold or hot??
I always check PSI with tires cold.
[QUOTE=clanter;8353451]
… is this 80 PSI when the tire is cold or hot??[/QUOTE]
Unless you’re on a racetrack, it’s cold pressure. This time of year you’ll need to add air to make up for the overall lower temperature.
As far as inflation pressure, I run mine mostly near the max. I’m not constantly adjusting tire pressure from trip to trip, and so I’d rather keep my tires at their maximum load capacity at all times. I’ll let the trailer suspension do the cushioning.
I don’t adjust and readjust either, once I find what works in general for a trailer or truck, or car.
i always inflate within 5-10lbs less than the max cold psi.
When people say “max” are they referring to the max psi on the tire or on the trailer? My trailer says 60 psi on a tab on the tongue but my tires themselves say 80 psi max on the sidewall. I run them at 60 but honestly this had always confused me!
[QUOTE=mbv;8356142]
When people say “max” are they referring to the max psi on the tire or on the trailer? My trailer says 60 psi on a tab on the tongue but my tires themselves say 80 psi max on the sidewall. I run them at 60 but honestly this had always confused me![/QUOTE]
It’s what’s on the tire that counts.
IIRC the max pressure rated is when the tire is cold. It’s my understanding that tires are engineered to safely handle the higher pressure that might develop on a hot day at high speed.
Is the max pressure the optimum pressure? Maybe so and maybe not; it depends on that your doing and where you’re doing it. Tom’s given some pretty good advice.
G.
^ correct with a bit of context:
- I always use the max pressure on a trailer tire. You can use less in some cases, but it’s not practical for most of us so the max pressure is safest.
- On a towing vehicle, inflate to the pressure on the sticker on the door but check that it’s the same or lower than the max on the tire. The tire max marking should be the same or slightly higher. Also compare the load rating of the tire to the door sticker - again it should be the same or slightly higher.
- On a passenger vehicle, inflate to the pressure of the sticker on the door. It should less than the tire max, and often is much less than the tire max. That’s ok - don’t use the tire max pressure in your car unless you like getting your fillings re-done.
We don’t inflate our tires to the max for reasons mentioned here plus we live on rocky roads and a drum-tight tire is more likely to get a puncture.
