Originally Posted by markopolo
I run 62 PSI front & 80 PSI rear.
Use the weight of each end or corner of the van and the load and inflation table for your particular tire to find the minimum PSI required to support the weight.
For my van, those minimums are approximately 65 PSI rear & 50 PSI front. My low pressure alarms are set above the minimum requirement and are 70 PSI rear & 55 PSI front.
My high pressure alarms are currently 95 PSI rear & 75 PSI front. I'll probably lower those a bit. I want it high enough to prevent unneeded alarms but still be useful.
The Tymate linked to in the first post lists the range as 0-87 psi - if the max alarm setting is 87 psi then it is probably a bit too low for most Class B vans. The tire pressure could exceed that as the tire heats up while driving. A PSI setting of approximately 10% over should be OK (in theory) from what I've read but you'll probably find that you often start the trip already over 80 psi if the pressure was set in the morning when the ambient temperature was much cooler. A PSI setting of approximately 15% over should avoid nuisance alarms.
My rear tires reached 85.9 psi on a 15 mile / 20 minute / back roads / somewhat overcast but high 70's ambient temperature trip a few days ago.
I left the high temperature alarm at the default setting.
Not on the temp numbers, but something that is very interesting concerning the minimum pressure rating charts.
As we often stress, this is the minimum pressure you should run, not the best for ride/handling balance or even safety, and Marko, like most of use is running higher than the chart pressures.
The interesting part is that the pressures he has chosen to use are at the essentially same ratio of pressure front/rear at 77%.
We have found that for best handling/ride balance we run 62/76 psi. Our interesting part is similar to Marko's. Our ratio is 81% and that is also the front/rear axle weight ratio for us.
I need to check the minimum pressure chart to see if that gives the same ratio for ours, I think, to see if it is the same also. If all three of those are the same, it kind simplifies narrowing in on the best tire pressures for individual vans, I think.