Tire pressure monitoring systems (TPMS) vs Automatic Tire Inflation Systems (ATIS)

I’m pretty sure the tire manufacturers have taken pressure rise into account when they set a recommended pressure
Well the engine manufacturers design them and spec oil type around the thermostatically controlled operating temperature. And the majority of engine wear occurs when the engine is cold.

So if the tires were supposed to be operated at their "hot" pressure, how about an electronic gizmo that keeps them at that pressure even when they're cold?

At some point though this becomes like a lot of things. The initial cost and maintenance of this system could well exceed the savings that one is trying to accomplish.
Unless you're @Mike. You have to add the nerd factor. He likes his electronic gadgets. When he's cooking on his BBQ grill, his phone tells him when it's done. 😁
 
Well the engine manufacturers design them and spec oil type around the thermostatically controlled operating temperature. And the majority of engine wear occurs when the engine is cold.

So if the tires were supposed to be operated at their "hot" pressure, how about an electronic gizmo that keeps them at that pressure even when they're cold?


Unless you're @Mike. You have to add the nerd factor. He likes his electronic gadgets. When he's cooking on his BBQ grill, his phone tells him when it's done. 😁
Because the rubber itself changes temperature. If it's too pressurized when it's cold it'll probably blow up, not being as malleable.
 
Because the rubber itself changes temperature. If it's too pressurized when it's cold it'll probably blow up, not being as malleable.
I don't think so because if that were the case, they'd never make it out of the truck stop parking lot in the dead of winter. Especially a steer that bulges out at the bottom.

I think this concept of maintaining a constant pressure when the tire is at outside air temperature on a cold winter morning or at running temperature at noon in July is worth looking into.

If course though, it'll have to be the running temperature of the tire that's maintained, not the "cold" temp.
 
Unless you're @Mike. You have to add the nerd factor. He likes his electronic gadgets. When he's cooking on his BBQ grill, his phone tells him when it's done. 😁
Damn right.

And if a tire is going flat, I would like to know about it at a 5psi drop, not when the thing breaks loose from the rim while driving. :)
 
Well the engine manufacturers design them and spec oil type around the thermostatically controlled operating temperature. And the majority of engine wear occurs when the engine is cold.

So if the tires were supposed to be operated at their "hot" pressure, how about an electronic gizmo that keeps them at that pressure even when they're cold?


Unless you're @Mike. You have to add the nerd factor. He likes his electronic gadgets. When he's cooking on his BBQ grill, his phone tells him when it's done. 😁
Have you ever been accused of over complicating things?
 
I don't think so because if that were the case, they'd never make it out of the truck stop parking lot in the dead of winter. Especially a steer that bulges out at the bottom.

I think this concept of maintaining a constant pressure when the tire is at outside air temperature on a cold winter morning or at running temperature at noon in July is worth looking into.

If course though, it'll have to be the running temperature of the tire that's maintained, not the "cold" temp.
If a tire isn't artificially messed with by a system, cold temperatures reduce PSI. In a parking lot in the freezing cold ambient temperatures, the PSI will read less than 110/100 or whatever it's normally set at. The less malleable rubber will be unharmed. As the tire warms up the PSI increases and you're back to where it belongs.
 
One thing that used to **** me off when I drove full time was the company's policy of every truck that enters the Iowa or Kansas yard gets pulled into the shop for a quick inspection regardless of why you're there. (Unless they're too busy)

And another policy requires them to completely fill the warm shop with as many trucks as possible in the winter before they go home.

Those are obviously good policies. But the part that pisses me off is they would check the tire pressures on a tire that's been inside the warm shop for a while, or even overnight, and let the pressure down to their specs. (steers 110, drives 105)

And then they'd park it outside.

Every time my trucks ever spent any amount of time in their shop in the winter, I'd come back from the hotel and the tires would be down about 7-8 psi.

And they get annoying when you pull up outside the door and grab an air hose to top off your cold tires. They say "we let air out because you had them over inflated."

If you explain the concept of the warm shop making the pressures increase, you get a blank stare and a repeated "but they were overinflated"..

:bonk:
 
That guy never gets anything done. Every time I see him he’s just sitting there.
Why do you think it takes me so damn long to get anything done? It took me 6 months just to build a heated workshop in a pole barn. 😁
 
Something to remember while pondering temperature-driven pressure changes is that while there is a linear relationship between pressure and temperature, the temperature needs to be in Kelvin. 0° C = 273K.

And that is your nerdgasm for today! 😁

SmartSelect_20201124-223257_Google.jpg
 
Hopefully it catches on enough mass production runs the cost down.
Doubt it.

Spoke to a company that runs the system. It cost them $10,000 per truck. Because the original product is made in Canada and the difficulty getting parts through customs, they keep spare systems on the shelf just for repair components.

The main reason they run the system is not for tire life but for performance because they are a concrete supply companyAnd they want to have the ability to air the tires down to 40 psi for sand or mud on a job site or as high as 110 psi for the road.
 


Figuring out the pressure to run, Michelin X-line energy D, 34,000 pounds divided by two axles and giving a 10% over safety comes up with a weight of 18,700 pounds. Going up instead of down the manufacturer recommends 90 psi inflation.

726E9BDA-FC4A-4465-BE98-11069438C585.png

This was 95 and 110 psi.

AB71A93E-3DE6-481C-8286-59DCE50ED505.jpeg
 
Last edited:


Figuring out the pressure to run, Michelin X-line energy D, 34,000 pounds divided by two axles and giving a 10% over safety comes up with a weight of 18,700 pounds. Going up instead of down the manufacturer recommends 90 psi inflation.

View attachment 75357

This was 95 and 110 psi.

View attachment 75359

Mismatched pressure across a dual isn't necessarily a representive pic of different pressures vs footprint
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Users who are viewing this thread

Top