TPMS false WARNINGS, self-induced
Started my day determined to even up tire pressures across the front and across the back. With my nine month old TPMS, and the first day of an extended trip starting, my purpose was to fine tune the pressures to more adequately monitor the rubber in route. My goal was 105 psi up front and 100 psi across the back. In spite of being an old man I was pretty proud of my results; a bit high up front, (106 and 108), but the rear came out just about a perfect 100 psi across all four.
So off we go about 5 hours later departing mid FL with an OAT of 95.
About 1 hour into our journey to cooler air up north I get a warning from my TPMS. Left front had hit 120 degrees. Of course with my senior memory I had forgotten where I had set the warnings when I first installed the TPMS. After comparing the left front psi readout from the TPMS with that with a real tire pressure gauge I confirmed the pressure was very near to 120 psi. With the frustration of getting the warning and confirming the pressure with a gauge I let a few psi out of the tire and continued our trip up I-75.
Most of you are way ahead of me now but within another 45 minutes I get a warning on the right front tire. TPMS indicates it’s at 120 psi. How that saying go, - fool me once shame on you, fool me twice shame on me. So I just watched it and turned the warning off. Meanwhile, DW was helpful in reviewing the instructions for the TPMS and it dawned on me I had used the manufactures recommended 15% above and 10% below recommendation when setting up the alarm feature. Had I used a 16% above or had I set my front tire pressure AT 105 instead of accepting 106 or 108 as good enough I never would have received the warning or experienced the frustration of [moderator edit] is going on here. I watched the right front psi for another 5 hours and it stayed right at 121 psi. Left front having been bled a few pound ran at 117 psi. Of course I’ve now changed the warning threshold for the front tires to 123 psi. I believe rolling along at 63 mph in 95 degree temperatures is about the max I will experience in the future. On day two of the same trip with same hot OAT of 95+ degrees I noted that the psi rise on all six tires averaged 16 to 18 psi.
I made a mistake in my TPMS setup. The whole purpose of this diatribe is to share that mistake to help others as I have benefited reading other informative confessions on this site. But help me out here. I figure I have this season only before replacing all tires. 30,000 miles, tires are 6 years old based on manufacture date on sidewall. Do you think my plan on waiting till the 7th year before replacing all six is a reasonably safe plan? Tires look great in that they show no sidewall cracking or other symptoms of being over the hill?
2012 Phaeton 40 QBH, 2011 Ford Explorer & 2013 Jeep Wrangler Toads via BlueOx, TPMS by TTS, Delta Force toad brake system.