Greyhawk TPMS

[Griswald One]

Hello All, Quick question about Greyhawk tire pressures and TPMS. What pressure do you have your tires set at generally and what range do you set your alerts on a TPMS.

I was clueless when I put my TPMS on the rig. I carefully adjusted all six tires to 80lbs and then added my Sensors and programmed the alarms to go off at below 73lbs or above 87lbs.... Those of you who no more about tires then me can stop rolling on the floor laughing now ... I don't think I had gone more then 10km and the bells and whistles were going off.

So do you fill them to 80lbs cold? Do you then adjust in trip if you move to warmer climates? And how high is to high on the highway? I think I have the alarm set at 96lbs now. So far on fall/spring trips on Canadian highways I have not exceeded that. Will my trip to Myrtle Beach in August have me singing along to the alarm bells again? Should I be setting the pressure higher?

Thanks in advance for your thoughts!

[MadDad]

Get to the web site for the tires you have, the RV pressure site, and print out the chart. Load up the rig as if you were heading out on your trip. Go to a truck scale and get the front and rear axle weight. Check the chart for the recommended pressure for the weight of the axles.

[hoppers4]

The michelin tire chart for the weights on my rig calls for 75 lbs front single, and 80 lbs rear dual. I've been over the scales several times and this is the best pressures for my rig when loaded for travel. Michelin tire chart for XPS rib Tire and Retread Selector | Michelin Truck

I don't worry about changing pressure with changing temps. I just make sure there's no tire with low pressure the next morning. I don't put much stock in the temps as measured by the TPMS. In no way do they measure the internal tire temps as they're on these long extensions and they're outside of the tire.

[norty1]

I set mine at cold pressure of 100 on trailer, 80 on rear truck and 60 on front truck tires.

Alarms are all set for 10psi low and 20 psi high.

[Griswald One]

Thanks for the input and particularily the link to the chart. My numbers are going to be the same as Hopper's...75lbs front axel and 80lbs rear. So that part is good. Your note about tire temp via the sensors also seems logical, that being said tire pressure would seem to tell us a lot about what the temperatures are doing.

So the next question is what to set my upper alarm at? At what point does the tire pressure become a concern. Is there somewhere to learn the "Hot Maximum" versus the listed Cold maximum?

[norty1]

The Michelin standard is 157 deg F.

[Jopopsy]

I took mine over the scales twice; 80 in the back and 75 in the front give me a margin of safety in weight for whatever imbalance I may have side to side.

I do check my tires at the start of every trip. I prefer to check them the night before after the sun has been off the tires for a few hours.

I don't use TPMS - I figure if I'm shy of my GVWR, shy of my GAWR for both axles, and I've been good about checking my pressures before I'm underway - hopefully that translates into being good on the road.

[ChristopherW]

Hello Griswald, I bought my TPMS from TST (Truck Systems Technologies) and they did the programming for me. Their recommendations for the 80 lbs tire pressure my Greyhawk 29KS manual recommended were:
High: 104; Base: 80; Low: 72
BTW, I love having this unit when I travel, especially when towing my boat as I could never detect a tire problem on that dual axle trailer. The TPMS unit detected a slow valve stem leak on the first trip after our purchase. That allowed me to top off the tire in the campsite with my portable compressor and make it back home to a permanent fix by the tire shop.

[Griswald One]

Originally Posted by ChristopherW

High: 104; Base: 80; Low: 72

Thanks ChristopherW. Those are the numbers I was looking for. And I definely agree with the value of the TPMS. On a long haul it adds to my comfort level and it is one less thing I need to remember to check before each trip since the monitor is giving me constant feedback.