This topic always has me scratching my head and wonder if I am alone.
Our PC is equipped with these tires. Michelin LTX M/S LT225/75R16
They are the originals with over 38,000 miles and now 12.5 years old. I will be replacing them before our next big trip.
Here is the max-load condition of our PC, weighed on a truck scale. Note the following
- front axle places 1630 pounds on each front tire
- rear axle places 2055 pounds on each rear tire.
According to the Michelin chart here
- 1630 pounds per front tire states they need 41 PSI.
- 2055 pounds per rear tire states they need 62 PSI
When I inflate the front tires to 41 PSI, they look terribly under-inflated. My rear tires don't look as bad, but still so. Because all tires look so low, I always add more air, inflating the front tires to 65 PSI (24 PSI extra) and the rears to 67 PSI (5 PSI extra). Doing so, then they look better, still under-inflated, but better. The rear tires have worn evenly, the front tires would have worn evenly except my front shocks were bad for a while which messed them up.
Am I the only one adding extra air?
Michelin provides a different chart for RVs, the primary difference is weighing each corner, taking the heavier of the two and using that PSI figure for every tire on the axle. But since I have not yet found a place to weigh each corner, I resort to "axle weight" alone.
I wonder if there is that much of a difference between the heavier corner weight and axle weight divided by two. To you who have weighed axles and corners, what are the differences you see?
