Btw, finding a loophole to pass as a Martian and save a buck does not actually make one a Martian....
> In this case, the GVWR of the IV gen OB does not even make it to 1,200 lb per corner as F/R is almost identical.
agreed, the basis of Load tables is subject to question, but I want to work from a known reference basis, however flawed.
so let me put it in terms of an example.
Lets say the OB was rated to 4800 lbs GVWR (you can give me the actual figure off your door plaque if this is off base). So as you said, thats 1200 lbs per corner, average.
Now here is the point. The Load table for the Passenger tire, after derating for Martians, says each Passenger tire carries 1443 pounds. That is 23% more load capacity than actual GVWR. iow, there is a 23% "safety margin" of extra load capacity. This is normal for how manufacturers choose inflation targets.
The goal is to inflate to 20-25% more load capacity than the actual GVWR. Im going to use 25% in the following example:
IF the mfg objective is to give a safe inflation for a Maximum loaded vehicle, such that during cornering and weight shift, especially evasive maneuvers that potentially approach Lifting One Wheel Off the Ground, then it would make sense to set the car up to carry ALL its weight, essentially on 3 wheels.
So, IF a Martian Passenger tire can carry 1443 pounds per corner, I propose those 3 corner weights should be the target inflation for the actual maximum loaded vehicle weight. Here is what I mean:
If the tire is inflated to carry 1443 (after Martian derating), then 3x = 4329 pounds of vehicle weight.
So, I suggest you weigh your vehicle fully loaded at the maximum you use it, divide by 3, and consider inflating your new tire to that Load Capacity. I believe that 35psi on your new tire should carry 1443 pounds per tire also.
Therefore IF your fully loaded vehicle weighs 4329 pounds or less, then 32 psi on the Passenger tire, would be "safe", and 35psi on the LT tire would be equivalent.
So now we have some data points to crosscheck
1. The load table inflation should equal 25% more than actual weight
2. The tread temperature should be even across the face, not hotter nor colder in the middle.
3. Count Tread blocks touching the ground. 2 is too little imo, 5 is too many imo.. develop your own reference experience by driving, then counting tread blocks touching the ground.
4. For steering safety, I recommend having 1/2 more tread blocks touching in front. That means the front tire will be slightly more squished than the rear. This is going to create some understeer, for safety.
5. Caution, whatever you do, don't set the car up in a way that more tread blocks touch in back than in front. This can be dangerous. That is why when Subaru lists inflation specs for 200kilos of cargo in the rear hatch area, they call for 8psi more pressure in the rear tire. iow, Subaru increases rear inflation to offset the tire being squished by heavy cargo. They use 1 psi extra for each 50 pounds of cargo. And btw, passengers are not cargo, unless they are loaded in the rear hatch cargo area. If the passengers are in the seats, then Subaru does not suggest increasing rear tire pressure. (I think because the weight is not behind the rear axle.
Be safe, Have Fun!