Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

1 - 12 of 12 Posts

·
Registered
Joined
·
536 Posts
Discussion Starter · #1 ·
Within days of getting my JKUR I aired the tires down from 41 PSI to 37 PSI. The TPMS read 37/38 PSI as well as my tire pressure gauge. The TPMS now says 40/41 PSI but I checked with two gauges and they both say 37 PSI. All tires were cold both times. So how accurate is the TPMS?

I did not start the Jeep this morning, but just turn the key to the ACC position. Should I have started it to get a new reading? Could it have just been giving the reading from when I parked it last night?
 

·
Registered
Joined
·
3,112 Posts
I don't think they are too accurate myself.
I believe the first reading (start up) is from memory of the last input. I think the system gets all new input from the sensors after start up each time.

While my tires are usually at 37 to 40 psi my TPMS can read as high as 41 -42 psi. Most often the same PSI isn't shown across the display even though the pressure in the tires are equal.

Maybe they round up/down the actual input?

I only use mine as a reference. As long as they read close I don't worry but if one starts to show a significant decrease, it is usually correct in indicating a leak.
 
  • Like
Reactions: jp4me

·
Registered
Joined
·
150 Posts
Who knows. I keep an old fashioned gauge that looks like a large round pen barrel if you have ever seen one to check psi and it has been close to right on every time with the TPMS and maybe within .5 to 1 psi every time.
 

·
Registered
Joined
·
877 Posts
There's another recent thread on the same subject. Believe I included a link there for a pressure gauge I have two of that are very accurate. My TPMS dash readings are accurate, within 1 psi. You have to drive for a few minutes to get a current pressure reading, can't just turn it on and read it.
 

·
Registered
Joined
·
23,965 Posts
^^^ What he said. At first morning start up, TPMS is reading the last nights shut down until you drive a few min. For the new reading to take affect. That said... as tire temps go up (from driving) so will the air pressure. The TPMS will capture this also.

Always keep an actual gauge in the glove box For peace of mind.

If I wanna fun a certain psi. Say 33psi.. I will lower the psi. 2-3lbs (30-31) for heat build up. When the tires get warm after driving a little, blamo... I am at my target psi.
 

·
Registered
Joined
·
536 Posts
Discussion Starter · #7 ·
upon start up, it displays psi where it was when you last shut it off. mine usually takes a min or 2 after driving to display current psi readings.
Drove it out and checked after a couple minutes and the pressure readings had come down to just above what they should have been.
 

·
Registered
Joined
·
10,420 Posts
I did not start the Jeep this morning, but just turn the key to the ACC position. Should I have started it to get a new reading? Could it have just been giving the reading from when I parked it last night?
To save battery power, the sensors don't even transmit until/unless they are spinning/rotating.
 
  • Like
Reactions: Heavy-Metal

·
Premium Member
Joined
·
16,902 Posts
I have found them to be extremely accurate (in all my Jeeps) same has held true with all the read-outs to include outside temperature.
 

·
Registered
Joined
·
877 Posts
To save battery power, the sensors don't even transmit until/unless they are spinning/rotating.


I can sit in my 2016 JKURHR enjoying the AC while I air my tires up after driving trails and watch the tire pressure change with 2 compressors running, so I know when to get out and turn them off or change tires. Maybe the sensors shut down after a while of inactivity, but the wheels don't have to be turning for the sensors to give real time readings on the dash display while parked.
 

·
Registered
Joined
·
10,420 Posts
I can sit in my 2016 JKURHR enjoying the AC while I air my tires up after driving trails and watch the tire pressure change with 2 compressors running, so I know when to get out and turn them off or change tires. Maybe the sensors shut down after a while of inactivity, but the wheels don't have to be turning for the sensors to give real time readings on the dash display while parked.
I don't know if there is some delay in their turn-offs, but there have been lots of reports here posted by people complaining that they stop at the 'station to fill their low tires, and that the EVIC doesn't change at all even though they aired up to 60lbs (by accident).
 

·
Registered
Joined
·
121 Posts
I despised TPMS when it first came out, but I've grudgingly come to appreciate it, so much so that I've forked over $ to have it put on several sets of winter wheels/tires on a few vehicles over the years. When you get a screw/nail slow leak it can save you a lot of hassle as it becomes an early warning system. I've found TPMS to be quite accurate as well.
 
1 - 12 of 12 Posts
Top