What r u guys running psi?

[Crusty old shellback]

I used the AphaOBD and lowered my to like 20 PSI. That way I can air down when off road.

 

[Cpsram21]

2020 SWR LB CTD. I run 65 front and 50 rear unloaded on stock 18’s and Transforce. Pulling 14k+ 5er I fill up rear to 80psi. I’m switching to Fuel wheels and Toyo 35’s next week and from the data charts I’ve seen on them pressures will stay about the same.

I have the fuel wheels and 35x12.50-18 tires , I run 50 front and 45 rear unloaded but the tires are 12 ply so don't need as much. I air up to 65-70 rear and 65 front when pulling my 14k bumper pull enclosed trailer or wood trailer. Before i removed the transforce i ran them at 65 front and back unloaded.

 

[AH64ID]

I have the fuel wheels and 35x12.50-18 tires , I run 50 front and 45 rear unloaded but the tires are 12 ply so don't need as much. I air up to 65-70 rear and 65 front when pulling my 14k bumper pull enclosed trailer or wood trailer. Before i removed the transforce i ran them at 65 front and back unloaded.

Being 12 ply doesn’t mean they need less air for the load.

The ply rating (remember they don’t actually have 12 plys) doesn’t effect low load pressures. In your example with 35x12.50-18 a D, E, and F rated tire all can hold the same weight at 50 psi, 2910 lbs. The main difference in all 3 is the max pressure, which limits their max weight.

The D rated tire is limited to 50 psi.

The E and F rated tire can both hold the same weight at 65 psi, 3415lbs.

The E rated tire is limited to 65 psi.

The F rated tire can go to 80 psi and hold 3970 lbs.

 

[CdnHO]

Being 12 ply doesn’t mean they need less air for the load.

The ply rating (remember they don’t actually have 12 plys) doesn’t effect low load pressures. In your example with 35x12.50-18 a D, E, and F rated tire all can hold the same weight at 50 psi, 2910 lbs. The main difference in all 3 is the max pressure, which limits their max weight.

The D rated tire is limited to 50 psi.

The E and F rated tire can both hold the same weight at 65 psi, 3415lbs.

The E rated tire is limited to 65 psi.

The F rated tire can go to 80 psi and hold 3970 lbs.

E rated tires are limited to 80 psi. D is limited to 65 psi and the F to 95 psi.

 

[AH64ID]

E rated tires are limited to 80 psi. D is limited to 65 psi and the F to 95 psi.

Not in all sizes. Many of the larger floatation sizes are as I listed. My example was specific to the 35x12.50-18 being referenced.

 

[CdnHO]

2500 or 3500?

3500's have TPIS and won't ever set off a warning.

2500's have a warning like the 1500, but I don't know the threshold. You can edit it with AlfaOBD too.

I changed my dually to TPMS so I now get a low pressure warning. Not sure why they don't enable TPMS at the factory, except maybe the law doesn't require it. As far as pressures go, I used the Cat Scale weights of both the truck and trailer along with the Load/Pressure table. I do add 10 psi to the trailer as the thing is heavier on the driver's side. With the fiver hooked up, the required pressures are pretty close to what the door sticker says. Unloaded, I run 35 psi in the rear duals. But I digress.

 

[AH64ID]

I changed my dually to TPMS so I now get a low pressure warning. Not sure why they don't enable TPMS at the factory, except maybe the law doesn't require it. As far as pressures go, I used the Cat Scale weights of both the truck and trailer along with the Load/Pressure table. I do add 10 psi to the trailer as the thing is heavier on the driver's side.

I have thought about enabling TPMS, but the thread hold would be pretty low since I run 25-80 psi on my rear axle, so I’m not sure the warning would be early enough if loaded. I generally keep the tire pressure screen up.

My dad does want me to convert his TPIS to TPMS thou.

 

[CdnHO]

I have thought about enabling TPMS, but the thread hold would be pretty low since I run 25-80 psi on my rear axle, so I’m not sure the warning would be early enough if loaded. I generally keep the tire pressure screen up.

My dad does want me to convert his TPIS to TPMS thou.

I change the pressure threshold depending on if I am towing (65 psi) or unloaded (35 psi). I use J-Scan (IOS) and only takes five minutes. I assume AlphaODB does the same thing. I just like to know if there is a tire issue without having to have the screen up on the EVIC all the time. That said, I only need to change it four times a year. If you were airing down every weekend, it would get to be a pain. I am always paranoid about tire issues, so it is nice to have the TPMS on both truck and trailer.

 

[AH64ID]

I change the pressure threshold depending on if I am towing (65 psi) or unloaded (35 psi). I use J-Scan (IOS) and only takes five minutes. I assume AlphaODB does the same thing. I just like to know if there is a tire issue without having to have the screen up on the EVIC all the time. That said, I only need to change it four times a year. If you were airing down every weekend, it would get to be a pain. I am always paranoid about tire issues, so it is nice to have the TPMS on both truck and trailer.

That’s a good point, I only run 25 psi once a year. I do frequently go from 35 to 65 thou.

 

[unclelala]

Semi-related, how accurate is the Ram tire pressure display? This afternoon I used my Viair gauge to check the tires and the Ram display is approximately 3 lbs. more on all 4 tires

 

[CdnHO]

Semi-related, how accurate is the Ram tire pressure display? This afternoon I used my Viair gauge to check the tires and the Ram display is approximately 3 lbs. more on all 4 tires

I use a 200 dollar pressure gauge and the display is nowhere near accurate. Close enough for indicating an issue however.

 

[AH64ID]

I use a 200 dollar pressure gauge and the display is nowhere near accurate. Close enough for indicating an issue however.

What percentage of error are you seeing?

On my cheaper, but not cheap, gauges the difference is less than 2%.

 

[H3LZSN1P3R]

What percentage of error are you seeing?

On my cheaper, but not cheap, gauges the difference is less than 2%.

Thats the same as i see with my way overpriced snap-Off gauge

 

[CdnHO]

What percentage of error are you seeing?

On my cheaper, but not cheap, gauges the difference is less than 2%.

Depending on the tire, I am seeing up to ten percent error.

 

[AH64ID]

Depending on the tire, I am seeing up to ten percent error.

Do you have the selectable tire fill alert?

 

[CdnHO]

Depending on the tire, I am seeing up to ten percent error.

That said, most tires are close but I have one that is way off by 6 psi. I trust my gauge however. They also seem to vary a lot while running down the road. By "a lot" I mean up to three psi on a tire. Sunshine and pavement temps probably account for some of this.

 

[CdnHO]

Do you have the selectable tire fill alert?

Yes, But never used it. Easier to use a gauge.

 

[H3LZSN1P3R]

Do you have the selectable tire fill alert?

I have it and it does not work no matter what i try i have followed the instructions to a T and i can not get it to work.

My nissan has a similar system and it works great

 

[AH64ID]

Yes, But never used it. Easier to use a gauge.

I was mainly wondering because there is a difference in the TPMS sensors. I find the non selectable tire fill ones take a mile or two to read correctly, but the selectable tire fill ones always read well.

I like it for when I’m using my OBA and just clamp the tire chuck onto the valve.

I want to change the sensors in my 18’s for hunting to the selectable tire fill version.

I have it and it does not work no matter what i try i have followed the instructions to a T and i can not get it to work.

My nissan has a similar system and it works great

Interesting. I really like it, in fact I was using it yesterday.

I really don’t like that I have to enable it in two places every time I use it thou.

 

[H3LZSN1P3R]

I was mainly wondering because there is a difference in the TPMS sensors. I find the non selectable tire fill ones take a mile or two to read correctly, but the selectable tire fill ones always read well.

I like it for when I’m using my OBA and just clamp the tire chuck onto the valve.

I want to change the sensors in my 18’s for hunting to the selectable tire fill version.



Interesting. I really like it, in fact I was using it yesterday.

I really don’t like that I have to enable it in two places every time I use it thou.

I wish it worked i may try again one day but not holding my breath