Tire pressure sensor accuracy

[Davidmurphy02]

This is the first vehicle I've owned with individual pressure readings on each tire. For those of you who have had this feature for a while, how accurate do you find the sensors to be? I was getting some different readings so this morning I set each tire to 38psi, measured with a high quality analog gauge on the valve stem. Then I checked the dashboard display - 2 tires read 39, one 37, and one 40. Is this just a normal variation - is it unreasonable to expect a high degree of accuracy from the tire sensors? All four are within 2 psi of actual....I was just hoping for better accuracy than this.

 

[Edwards]

Can't comment on the Ram's sensors but they can be very accurate. My 2011 E550 is accurate to the lb. I ran my tires too full for a year trusting my expensive gauge only to find out that it was off and the Mercedes sensors were dead on.

 

[356]

My experience with my previous Ram is that the system was very accurate...within 1# of my commercial grade gauge. Although the users manual says to not rely on this system, I found it to be very useful for tire maintenance. With the new inflation system that honks the horn with the target pressure has been reached, it is even better.

As an aside, I had a hay-hook go through a tire on my previous RAM. Since I was on a dirt road, I didn't notice it, but the warning came on about 5# from normal and I was able to watch the count-down, which informed me that I had enough time to get out of the field and onto a road (I was at 10# when I hit the road). If I had only had a warning, I would have stopped, checked the tire, and by the time I got back into the truck, would have been stuck changing the tire in a field.

The sensors seem to go off about 5# from "normal." This is important, as if it is too sensitive (as on our old Mini Cooper and Corvette) the sensors go off when the weather has dropped 20 or 30 degrees. This was never a problem on the Ram.

 

[Davidmurphy02]

Update to my original post - I've found that the sensors tend to need a couple of minutes to warm up and register properly when I start driving and then they are very accurate. The tire pressure goes up while driving, and they tend to retain the higher pressures in memory when I turn the truck off. The next day they still initially read high even though the tires have cooled down, but within a couple of minutes they adjust and begin to give accurate readings.

 

[VectorZ]

I find them spot on.

 

[Dietz5285]

In the winter they are a PIA

 

[VectorZ]

Filling with 100% nitrogen helps too.

 

[392DCGC]

Should be pretty darn accurate. There's a tire fill mode (search the manual) that you can put the truck in to alert you when a tire has reached the correct pressure. Must be accurate for that to be worth a damn to use.

 

[fishinfreak68]

Filling with 100% nitrogen helps too.

78% of the atmosphere is N2. So as you're adding N2 how does the residual air get out so you know for sure it's 100% N2?

Sent from my SM-N975U using Tapatalk

 

[securityguy]

78% of the atmosphere is N2. So as you're adding N2 how does the residual air get out so you know for sure it's 100% N2?

Sent from my SM-N975U using Tapatalk

Nitrogen is a bunch of BS...just fill the tire with air and call it a day!

 

[VectorZ]

78% of the atmosphere is N2. So as you're adding N2 how does the residual air get out so you know for sure it's 100% N2?

Sent from my SM-N975U using Tapatalk

I believe the system automatically adds nitrogen/removes O2 and moisture until it's at least 95%.

 

[VectorZ]

Nitrogen is a bunch of BS...just fill the tire with air and call it a day!

Costco does nitrogen fill for free. Here in Alaska where it gets -25° it's an added benefit to not add more air to keep them at the right pressure during severe cold.