CapriRacer wrote:
I don't think inflation pressure would have any affect on those wheels. Those cracks are no where near the flange, which is where inflation pressure would have the greatest effect.
So while it is likely a good idea to replace those wheels - or at least monitor them - I don't think they preclude the use of higher inflation pressures.
Here is the info on the wheels on that year/model Cardinal:'
16x6 8-6.5 0 3580 Clear Coat / Polished
Wheels are rated to 3580 pounds each. A heavier stiffer tire like the G614 is only going to stress the spokes of these wheels more. I am sure a call to Tredit will have them advising against installing G614 tires on them.
These larger Cardinals in that year range were under tired and wheeled. Fix it right with new 16" wheels and G614's or 17.5 rims and tires. Cardinal is now using Tredit's T09 8 spoke wheels rated to 3750 on all of their trailers(thanks to input from the Cardinal club). Even those that come with GY Marathon's are coming OEM with the higher rated wheels, and G614's are a factory option available(again from input from the Cardinal Club).
On another note, I am seeing that you are nibbling around the corners of the fact that tire pressure, speed and load ratings can be manipulated allowing one parameter to offset another.
Michelin is doing that with the 215/75R17.5 XTA which is being installed OEM on 5th wheels. It carries a 100KM speed rating(62MPH), 120 inflation and 4805 lb load rating. Michelin is saying the speed can be increased above 62MPH by reducing the max load below 4805 lbs. This drives one poster crazy, however it is according to industry guidelines/standards. There are charts for some tires that allow extreme loads at very low speeds.
This is why I have long felt the Michelin XPS Rib(and BS R250) when used at RV speeds(75 and below, Michelin list that speed for RV use) is more capable than it's 3042 rating and/or can be used safely right up to it's max rating without concern.

Guess what, this is how the ST tires get a higher rating!!!
Chris