Tire pressure

[Russellvh]

In the last 5 (+ -) years I have read a lot of information on tires and pressure. Since I have a 5th wheel and not a coach I’m basically questioning travel days. I sit for 2-3 weeks then travel at highway speeds for 6-8 hours and park again. I’m really not asking about what pressure to use as much as how to program it.



The TPS says to set the low pressure alarm to 10% below the cold pressure. Follow me here. If the tires cold temp is 80* then the low pressure should alarm at 72. BUT, especially, this time of year, the temp the next morning could be in the 60’s or lower. Also, the next day the pressure can top 100. Do I look at but disregard morning pressure until the tires warm up.

 

[Rollin Ollen]

In the last 5 (+ -) years I have read a lot of information on tires and pressure. Since I have a 5th wheel and not a coach I’m basically questioning travel days. I sit for 2-3 weeks then travel at highway speeds for 6-8 hours and park again. I’m really not asking about what pressure to use as much as how to program it.



The TPS says to set the low pressure alarm to 10% below the cold pressure. Follow me here. If the tires cold temp is 80* then the low pressure should alarm at 72. BUT, especially, this time of year, the temp the next morning could be in the 60’s or lower. Also, the next day the pressure can top 100. Do I look at but disregard morning pressure until the tires warm up.

We have a motorhome but I suspect the procedure might be the same. We had our axle weights measured and from there calculations were made about setting the pressures. The coach tires are set at 90 psi and the towed at 40. I can't remember the lows and highs for the alarms anymore but I suspect the 10% were probable right. Being from Canada, we experience some pretty low temps (even in the summer months) and, since we winter south, we get some pretty high daytime temps. I have not had any alarms.....touch wood or as those from the south would say...knock on wood. I think loaded weight measurements need to be taken in order to properly determine presures.

 

[TheLooks]

I get what he is saying. I have to constantly change my baselines with a TireTrakker 600 to prevent alarms.

 

[cptqueeg]

The TPS says to set the low pressure alarm to 10% below the cold pressure. Follow me here. If the tires cold temp is 80* then the low pressure should alarm at 72. BUT, especially, this time of year, the temp the next morning could be in the 60’s or lower. Also, the next day the pressure can top 100. Do I look at but disregard morning pressure until the tires warm up.

I don't understand how 10% of the temperature in degrees( °F) subtracted from psi (lbs per sq inch) makes any sense at all.

 

[Russellvh]

Sorry, good catch. I should have said “if the tires cold pressure is 80psi…

 

[DennisT]

Never pulled out with the low alarms actually on. If it was cold I’d fill to just above the alarm before travel.

 

[TheLooks]

Yes, but then you push the high temp alarms. This has been an issue only on my front tires, although one back inner tire likes to run warmer. I have replaced the calipers and pads and flushed the fluid thinking this was a brake issue.