Tire pressure
Correct tire pressures on motorhomes are essential for good handling and to prevent premature failure. Tire pressures should be determined from the tire manufacturer’s inflation chart. The first step is to obtain scaled weights of the motorhome, preferably all four corners of the RV, so you can determine the load on each tire.
Tire life
RV tires rot out long before they wear out. The industry accepted tire life before needing replacement is 7-10 years from the date of manufacture. The latter can be determined from the date code on the sidewall of each tire.
Tire Manufacturing Date Codes
Exposure to sunlight, ozone, and ultra-violet radiation causes gradual loss of the plasticizers that keep the tires flexible. Sidewall cracking can often be seen but may not always be apparent. So, for the sake of safety and to avoid sudden catastrophic failure, replacement should be done on an age priority basis. This does not mean that obvious tread wear, sidewall damage, or any other physical problem with the tires should be ignored if they still have x years to go before they are too old.
When buying new tires you should require that all tires have the same date of manufacture, and that that date should not be more than a few months prior to the date of purchase.
Beginning July, 2000, the NHTSA requires a 4-digit manufacturing date code that must appear on the sidewall of all tires sold in the USA. The date code is part of a longer code:
DOT MMM SS TTT DDDD where MMM is a 3 digit manufacturer ID; SS is a tire size 2 digit code; TTT is an optional tire type code; and DDDD is the date of manufacturing code; The first 2 digits indicate the week of manufacture and the second 2 digits are the year, i.e.: 1820 would indicate that the tire was manufactured the 18th week of 2020.
Tires manufactured before July, 2000 had a 3 digit date code where the first 2 digits are the week of manufacture and the last digit is the year.
Tire pressure monitoring
A TPMS (tire pressure monitoring system) includes sensors screwed onto each valve stem, and a monitor panel on the dash. Some TPMS sensors include temperature monitoring in addition to tire pressure. The monitor can be set up to alarm at min/max pressures and temperatures.
If a TPMS system only measures/monitors pressure, a good investment would be an IR temperature gauge to check tire temperatures at every stop.