Tire pressures

[ezspdr]

I am new to this and have a question on tire pressure. The tires on the pick up say maximum 80psi cold and the tires on the TT say maximum 60psi cold. I have the front truck tires at 60psi, the rear tires at 70psi and the TT tires at 60psi.

Will this work or should I bring them up to the cold max? Thanks for the help.

[RickO]

Hi and welcome to the forum.

I'll leave your question to our trailer experts. For motor homes you have to get the rig weighed to determine proper PSI but I'm not sure how most handle it with trailers and tow vehicles.

Best of luck.

Rick

[Skip426]

Same rules apply , know your weights , set tire pressure accordingly.
Weigh the unit ready for travel, get a # for each axle , down load the tire manufacturers inflation chart and adjust accordingly.
Untill you have those weights you sound like your in the ballpark.
Just make sure all the breakables in the TT are tied down.

[FastEagle]

The correct tire pressure (s) - (recommended cold) - for your truck tires will be found on the tire placard. Exceptions will be found in the owner's manual.

The correct recommended cold tire pressure (s) for your trailer tires will also be found on it's tire placard. I don't know any manufacturers using less than maximum allowed pressures found on the tire's sidewall so I don't know what that 60 psi is. If it's less than the tire maximum you can increase it to the maximum. Never decrease it below the vehicle manufacturer's recommendations.

FastEagle

[JohnBoyToo]

I too vote for max pressure on the towable...

now for the tow vehicle...
inflate it to the level that will support more than the weight you are carrying...
that's vehicle weight, tongue weight, hitch weight, etc...

never be low !!!!

yes, going to 80 on your tv tires is ok,
and will get you the best mpg,
but it may ride like a brick

if your tires say they will support YOUR weights @ 65 lbs, run 70 and enjoy....

cold tire pressure is no driving for a while and really should be out of the sun in some of our climes

[SmokeyWren]

Originally Posted by ezspdr

I am new to this and have a question on tire pressure. The tires on the pick up say maximum 80psi cold and the tires on the TT say maximum 60psi cold. I have the front truck tires at 60psi, the rear tires at 70psi and the TT tires at 60psi.

Will this work or should I bring them up to the cold max? Thanks for the help.

You should use the manufacturer's recommendation for tire inflation only if you are too stupid to find and apply the load/inflation table for your exact size and type tire. Using the manufacturer's recommendation will guarantee you will almost always be overinflated. Overinflated tires means you will have a harsher ride and wear out the center of the tread much faster than if you properly inflated your tires.

Instead, use the correct load/onflation table for your exact tire. Those are hard to come by these days, because the vehicle and even the tire manufacturers all assume most folks are too stupid to apply the load/inflation tables developed by the TRA. But the load/inflation charts are identical for the same size/type tire sold in the USA, so use the tables from anywhere you find them. For examole, use the Maxxis charts for ST tires, and the Toyo tables for LT tires, regardless of whose name is on the tire.

Maxxis makes the load/inflation tables for the size ST tires they sell:
Trailer Load/Inflation Chart

Toyo makes the TRA load/inflation charts for LT and some other tires available:
Load & Inflation Tables | Toyo Tires

[FastEagle]

So called tire “load inflation” charts are primarily developed at the request of vehicle manufacturers and after market tire dealers/retailers. Their purpose is to allow vehicle manufacturers to make selections from pools of OEM tires that are compatible with vehicle requirements.

Tire retailers will use the charts to set acceptable tire pressures when “plus sizing” with replacement tires.

I’ve never seen a chart on the internet that has the accompanying steps of procedure for correctly applying the information on the charts. That’s probably because the procedures are best applied by trained and certified technicians. Bits and pieces of the correct way to apply the charts can be found in some of the major tire manufacturer’s tire data books.

To support what I’ve said I’m going to ask you to apply a little logic. Look on any of your vehicles certification labels or tire placards and find the governing factor for setting tire pressures (GVWR for motorized & GAWR for trailers). Then find the tire size and recommended tire pressure (s), remembering that the recommended pressure (s) you find are the MINIMUM standard for that vehicle. After doing some math you will find (almost 100% of the time) some load capacity reserves. Are you willing to give up any reserves you find? By setting the tire pressure to the heaviest end of an axle you forfeit all reserves for that tire.

DOT regulations requires the manufacturers of our everyday vehicles such as cars, trucks, SUVs etc. to have load capacity reserves. That regulation does not disappear with replacement tires.

RV trailers are swaying and wagging along behind our tow vehicles on narrow tires with - most often - very little load capacity reserves to absorb the tremendous forces inflicted upon them. Do you really want to give-up any load capacity reserves you have?

Trailer tires are designed with a shallow tread area to help dissipate heat. They are also designed to be operated at full sidewall pressure, ALL the time. That’s why the industry wide standard - with few exceptions - speed limit for them is 65 MPH.

Here is a reference about weights and pressures. In it you will find the statement - “Never use inflation pressures lower than those printed on the vehicle placard”. Remember, that is for the application at hand. There are exceptions found in the vehicle’s owner’s manual.

http://www.trucktires.com/bridgestone/us_eng/press/zip/WeighForm.pdf
　
FastEagle

p.s. I have had a personal conversation with Mr. Shaun Brennan from Maxxis tire Co. about load inflation charts for trailer tires. He informed me that the use of Maxxis tire load inflation charts for trailer tires is only acceptable with approval from the vehicle manufacturer. His phone number is 678-407-6772.

[JearBear]

I always use the max pressure on the tire. That gives me better stability and better tire life.

I just replaced six tires due to age and the tread was almost perfect on all six.

My tire tread always outlasts the suggested replacement dates and I never seem to have any tire problems.

[jpriest]

Good info, FastEagle. Not my thread, but I got a lot from it!

[ezspdr]

Thanks everyone for the feedback. I really appreciate the help. We are planning our first trip and this will ease some of my worries.

[SmokeyWren]

Here is a reference about weights and pressures. In it you will find the statement - “Never use inflation pressures lower than those printed on the vehicle placard”. ...

http://www.trucktires.com/bridgeston.../WeighForm.pdf

Notice the source: a tire company. The tire company lawyers all well remember the Firestone tire fiasco on Explorer SUVs a few years ago, so the tire company lawyers won't allow the tire company to put out info that requires someone to have more than two brain cells to rub together.

Yeah, they want you to overinflate your tires because that's a lot cheaper on them than to risk underinflated tires and the resulting lawsuits.

p.s. I have had a personal conversation with Mr. Shaun Brennan from Maxxis tire Co. about load inflation charts for trailer tires. He informed me that the use of Maxxis tire load inflation charts for trailer tires is only acceptable with approval from the vehicle manufacturer. His phone number is 678-407-6772.

Yep. More lawyer speak. The Maxxis lawyers won't allow him to tell you the truth.

You can use the load/inflation table provided you make sure you NEVER underinflate the tires for the load they are hauling. You want more fudge factor (safety margin), then inflate the tires 5 PSI or even 10 PSI more than the chart shows. But pumping up an LT load range E tire to the 80 PSI on the tire sidewall or the 65 PSI on the placard, when the TRA engineers say all it needs is 40 PSI to haul the load, is stupid.

[JohnBoyToo]

Smokey! chill bud - having a bad day in our Texus heat ?!?!

You are always full of great info, but seems like everyone is 'stupid' today

we are all just trying to help when you're not around to fully answer the question...

all this is predicated on knowing the exact weight at that moment...
and not all of us know that all the time since it has a tendency to change in our rolling rooms !

My definition of stupid is usually demonstrated in the beltway....