TPMS question

[Richard Shore]

We have just purchased the Tire Minder TPMS after suffering a flat tire and not realizing it. Ended up replacing two damaged tires. Les Schwab recommended 75psi not 80psi cold pressure. Should the Tire minder be set at 75 or 80 for alerts? We have a 2021 GD 2600RB.

[xrated]

We have just purchased the Tire Minder TPMS after suffering a flat tire and not realizing it. Ended up replacing two damaged tires. Les Schwab recommended 75psi not 80psi cold pressure. Should the Tire minder be set at 75 or 80 for alerts? We have a 2021 GD 2600RB.

First, I'll just say that "Les Schwab" doesn't need to make a recommendation on the trailer tire pressure. The trailer manufacturer, Grand Design has placed a safety sticker on the left front area of the camper with the recommended tire pressures that you should run. That is the tire pressure that should be utilized for your trailer tires, not from some tire dealer. Depending on how much the tire load capacity is, and how much weight is actually on each tire, you always run exactly what the trailer manufacturer has stated on that sticker. Having said that, I will clarify by stating that the sticker psi numbers are decided upon by the trailer manufacturer, not the tire manufacturer and certainly not a tire dealer. An underinflated tire has a much higher chance of failure than an over inflated tire does, but if the tires are inflated to the number that the trailer manufacturer has stated on the sticker, they will not be overloaded unless your trailer is overloaded.

Normally, the high pressure alert is set between 20% to 25% OVER what the cold inflation pressure is. In your case, 80 psi cold pressure should have an alert setting of 96 to 100 lbs. If you set it at 80 psi, it will be going into alert all the time because as the tire starts heating up when it's being used, the tire pressure will also be increasing.

And while we are on tire pressure alerts, the low pressure alert is normally set to 10% of the cold inflation pressure, which in your case is 80 psi. So set the low pressure alert at 72 psi and you will be good.

[Scott'n'Wendy]

I would set it at 95psi for high alert and 75 for a low alert. Inflate to 80psi cold.
Ignore tire shop recommendations. My tire shop just a couple days ago said I was crazy for spending the money for balancing trailer tires.........

[xrated]

I would set it at 95psi for high alert and 75 for a low alert. Inflate to 80psi cold.
Ignore tire shop recommendations. My tire shop just a couple days ago said I was crazy for spending the money for balancing trailer tires.........

I guess I'm crazy with ya....I had my new Sailuns balanced last year when they were mounted. Things that go round and round, at that speed need balancing.

[Hoopy Frood]

I'll have to join the club, I would have had mine balanced if I could have found a place to do it. Running the Centramatics in place of that.

[jadatis]

The sensors send pressure and temperature every 1 or 2 minutes to the receving unit with display.
But when sudden pressure loss of 2 psi sensor sends direct to the unit, and unit translates that as sudden pressure-loss and gives warning.

So the reason you bought tmps system for is always covered.

Then, if you can determine the axleloads in your use 99% acurate, by weighing fully loaded ( also the persons) as riding with, you can look them back in my made list, for the needed cold pressure.
And it might even give higher then 80 psi. Do you know the cource of the damaged tires? Might be overheating only once by to low pressure for the load and speed.

So first determine the needed pressure.
I make my lists with a formula even tighter then the official european for all kind of tires, and since 2006 also for P-tires in US.
Then I give directly 90% of calculated axleloadcapacity for the psi.
Determined this to give maximum ( absolutely needed for RV) reserve, but still acceptable comfort and gripp.

So then you " Only" have to determine tbe axleloads 99% acurate, the most tricky part, and your responcibility.

Need next from tires to make the list.
1. Maximum load or loadindex
If rear axle dualload for duall too.
2. Kind of tire to determine the referencepressure. Yours 80 psi is E- load
3 speedcode, less important, shall be Q or above for wich maxload is given for max 160kmph/99mph.

[LMagelitz]

We have just purchased the Tire Minder TPMS after suffering a flat tire and not realizing it. Ended up replacing two damaged tires. Les Schwab recommended 75psi not 80psi cold pressure. Should the Tire minder be set at 75 or 80 for alerts? We have a 2021 GD 2600RB.

I’m a fan of using the tire manufacturer’s load and inflation table for the weight the tire is carrying. I never go as low as they say is allowable, but I back off of “max cold.” I’ve blown quite a few tractor-trailer tires over the years inflating to max cold in the summer, but when I back off of that I seem to have better luck. This is anecdotal, of course. Our 310GK carries about 12k lbs on the axles, or 3k per tire. The left side is heavier, but I don’t know how much, so to be safe, I inflate to 105psi cold, or a little over 4k lbs per tire. The Grand Design sticker says 125psi cold, which is the max cold psi molded into the tire, so they took the worst case scenario of a per-tire loading of 4800lbs, or 19000lbs on the axles!!

Some would say if you overinflate for the load you are carrying, you will wear the center of the tire more than the outside, which does make sense. I will say after 20k miles, the Cooper Work tires on our 310 have a good flat profile.

I’d set the TPMS limits as others have suggested. And as always, YMMV, this is just what I do.

[jleonard]

I would set the low alert at 70 psi. I often start out at that pressure and within 10 minutes it's back to 78 to 80 as the tire heats up.

[xrated]

I would set the low alert at 70 psi. I often start out at that pressure and within 10 minutes it's back to 78 to 80 as the tire heats up.

You do understand that tire is engineered to be set at the max psi that is listed on the sidewall if needed and within that engineering of the tire, they are perfectly capable of going higher because of heating. It is basically not an acceptable practice to try and figure out where the tire is going to go and set the pressure lower, hoping that it will come up to the point that it should have been set to in the very beginning!

[Scott'n'Wendy]

I would set the low alert at 70 psi. I often start out at that pressure and within 10 minutes it's back to 78 to 80 as the tire heats up.

So long as your tires are capable of carrying the load your trailer puts on them when they are inflated to 70psi cold. You use a table like Larry does I guess?