Low tire pressure

[RalphReuter]

OK that time of year again. Tire pressure sensor is saying low tire pressure because of low temps! What are you guys doing with this, ignore, add air, or is there a fix to compensate for air temps? Thanks!

 

[lpennock]

Put air in is the correct solution, load rating is specified at COLD tire temp. There are charts to compensate between temps but the only time you need them is when you leave the vehicle in a heated shop and need to compensate for the fact the air is extremely code outside (like Alaska or Minnesota in winter). When compensating you will add air pressure to compensate for the pressure drop at extreme cold.

 

[RalphReuter]

Put air in is the correct solution, load rating is specified at COLD tire temp. There are charts to compensate between temps but the only time you need them is when you leave the vehicle in a heated shop and need to compensate for the fact the air is extremely code outside (like Alaska or Minnesota in winter). When compensating you will add air pressure to compensate for the pressure drop at extreme cold.

OK, but “cold tire pressures” at 80 degrees are far different than “cold tire pressure” at 30 degrees! Or am I missing something, cold tire I thought was a tire at rest, (over night) as opposed to checking pressure after running for 3 hours!

 

[Newsa]

I'm guessing you have the 2500 (tpms vs tpis), even though your signature isn't showing. You might need to pump the rears to 80 and the front's to 75 for the light to go off. That's the way my 2500 is (unless they changed it). Then you can let a bit out if the ride is too rough (you can let up to 15 psi out without triggering another low pressure light

 

[lpennock]

OK, but “cold tire pressures” at 80 degrees are far different than “cold tire pressure” at 30 degrees! Or am I missing something, cold tire I thought was a tire at rest, (over night) as opposed to checking pressure after running for 3 hours!

You are correct on what the definition of cold pressure is, pressure before runnning. What you are missing is how volume changes with temperature. As things get colder they require less volume. This causes the pressure drop you see between 0F and 80F. Since the volume of air has been reduced by the cold you have to add additional are to create the same volume which directly equates to the pressure.

TRA doesn't specify the cold pressure at a standard temperature (Scientists use 72F), they only specify it reference the tire not being run. So the "cold" pressure should be the same regardless of the outside temp being 0F or 80F.

 

[brucejohnson]

Here is a link to Goodyear tire site with a brief statement regarding the effects of temperature on tire pressure. https://www.goodyear.com/en-US/tire-guide/tire-care/how-cold-weather-effects-tire-pressure.

How Cold Weather Can Affect Tire Pressure
For every 10 degrees of temperature drop, tires will drop 1-2 pounds of pressure. It is important to keep your tires within the recommended PSI to maintain traction, handling and durability.​

The owner's manual also mentions temps:

Check tire pressures more often if subject to

a wide range of outdoor temperatures, as tire

pressures vary with temperature changes.

Tire pressures change by approximately 1 psi

(7 kPa) per 12°F (7°C) of air temperature

change. Keep this in mind when checking

tire pressure inside a garage, especially in the

Winter.

Example: If garage temperature = 68°F

(20°C) and the outside temperature = 32°F

(0°C) then the cold tire inflation pressure

should be increased by 3 psi (21 kPa), which

equals 1 psi (7 kPa) for every 12°F (7°C) for

this outside temperature condition.

Tire pressure may increase from 2 to 6 psi

(13 to 40 kPa) during operation. DO NOT

reduce this normal pressure build up or your

tire pressure will be too low.
​

 

[BigPapa]

The bottom line is, that when the temps go down, so does your tire pressure. No matter what the temperature, your tires are designed to run at a specific pressure range and you need to keep it there. If at 6:00 am it’s 30* and your tire pressure is 45psi, air it up to the proper pressure.

 

[Cummins12V98]

80psi in the rears is INSANE for an unloaded SRW.

 

[Newsa]

80psi in the rears is INSANE for an unloaded SRW.

The rears can run anywhere from 65-80 psi without triggering the low pressure light. But if thebrears drop to 64 psi or below on a 2500 with tpms, pumping them to 65 won't turn off the low psi light.... You have to inflate the rears to 80 psi to turn off the light. Once the light is off, you can let some air out

 

[lpennock]

80psi in the rears is INSANE for an unloaded SRW.

Yes it is. Dodge use to have a light/loaded switch and the government made them take it out. TRA pushed the government to mandate the TPMS had to trigger for Maximum payload. Government and TRA felt that tire failure due to overloaded for the pressure was more of an issue than increased stopping distance and tread center wear due ot to light of load for the pressure.

You can change the TPMS thresholds using AlfaOBD to a more reasonable value.

 

[TCDiesel]

Like Ipennock stated Use Alfaobd, You may need to change the country of Origin to "REST of World" then back to USA if still in warranty.

Its kinda of tricky, Make sure your Tire pressure is above minimum if 65 stay above this , drive for some time then change your minimum, just don't place it above with no driving then re-set. after re-setting, drive for some time then drop your Tire pressure, Not all vehicle need to follow this ,but its still the best way.

 

[SnoKing]

Yes it is. Dodge use to have a light/loaded switch and the government made them take it out. TRA pushed the government to mandate the TPMS had to trigger for Maximum payload. Government and TRA felt that tire failure due to overloaded for the pressure was more of an issue than increased stopping distance and tread center wear due ot to light of load for the pressure.

You can change the TPMS thresholds using AlfaOBD to a more reasonable value.

I had a big go around with Costco when they installed my new Michelin tires a couple years ago, saying that they could not set the rears at the pressure I requested. I pulled up the inflation chart and showed them the rating at 40 and 45 PSI. Sorry Charlie they get 80 PSI. I told them that they were pretty silly, as I would deflate them to the pressure I wanted before driving out of their parking lot! I have a clip on air chuck that I carry in the door pocket. Without a hose attached it makes a good deflater. I can tell when I am in the mid 40's as the sound of the air escaping changes. I go up and down on rear tire pressure many times each year based on the load I am carrying. Example, I inflated to 80 to pick up 3000+ pound pallets of wall blocks. BTW, stock rear 3500 leafs without any aftermarket help!

 

[lpennock]

I get the same thing with Discount tire except they will lower it back down for me. I tell them at the desk to set the tires on my 06 and 50f/45R then after they pull them out of the bay they are at 65F/80R. They will at least drop it down for me if I want them too. I just put my Staun Deflators on and set them myself in the time it takes to walk around the truck twice.

 

[TCDiesel]

How screw up is the US Gov, let see if your DEF or DPF triggers codes the count down of de-rate power begins to the point of NO operations.

When I owned brick and mortar Stores (Sold all of them YEY) owners would come in all the time with the TPMS lit and 3 out of 4 Tires at 20LBs or less and the vehicle allows operating...

Whatever the tire for MAX PSI or manufacture of the vehicles TP States the facility must follow.

 

[EricViviano]

MM3 tuners can also lower tire pressure warning light trigger to 29 psi if you are considering a tuner it's an added bonus.

 

[SnoKing]

I get the same thing with Discount tire except they will lower it back down for me. I tell them at the desk to set the tires on my 06 and 50f/45R then after they pull them out of the bay they are at 65F/80R. They will at least drop it down for me if I want them too. I just put my Staun Deflators on and set them myself in the time it takes to walk around the truck twice.

Staun Deflators, bit expensive, and I would only need two not four of the 15-55 range units. Would have to look for someone that would want to split a set. SnoKing

 

[lpennock]

Staun Deflators, bit expensive, and I would only need two not four of the 15-55 range units. Would have to look for someone that would want to split a set. SnoKing

I have 2 set for 50 and 2 set for 45. Don't need the 50 very often (other than when discount doesn't follow my instructions). Needed the 45 all the time when I was using my 06 to carry my cabover camper. Was constantly changing between 80 and 45 on the rear.

 

[Donnie Straps]

I used the Alfa app to change thresholds. Mine can go down to 35 psi before the light comes on. I did the chalk test on my tires to find the best pressure for those tires on my particular truck, (as tires ride different on different trucks) to get the best pressure and its not mac pressure on the tire or door of the truck.

 

[Boaring1961]

I run mine at 55-60 psi (cold) and ignore the warning light. I don't even notice it.

 

[Jim W]

I have a third gen with the TPMS in my 2008 truck. In the towing season, I use a different tire than standard. These tires and rims have no sensors install, dealer want to install sensors but I said no. I would not even pay for the sensors. So, the truck dings four times and idiot light is on doesn’t flash. Every trip I pull the trailer the rears are aired to 70PSI and the front is aired to 55PSI. When I run the Michelin tires in the winter the front our aired to 60PSI and the rear are aired to 45PSI.
I do not care what big brother states as to the air pressure required in my truck to operate safety, I know what is required to operate safety in an un-loaded pick up truck. I also check the air pressure once a month in the tires and adjust accordingly to what my pressure gauge states the tire pressure is regardless of ambient temperature.

This is my opinion and what I operate at