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- Plano, Texas, USA
All tires we've discussed here are SL tires. That's why I said you believe 35 psi is the maximum load pressure.⋯。Ill just list the relevant ones for the CX-5 which are P-Metric SL and XL.
SL is Standard Load and is rated at 35 psi (240 kPa)
XL is Extra Load and is rated at 41 psi (280KPa)
P-Metric is an old US tire standard which's only used in the US on some tires.
Yes there're many tire standards world wide, that's why the confusion.
And you still didn't answer the question on why all car manufactures use higher than 35 psi for heavier load? Again physics say tire pressure and load carrying are in direct proportion, that's why car manufactures are always recommending higher tire pressure for heavier load and faster speed, as long as the maximum inflation pressure allows. Maximum load pressure definitely is not set at 35 psi. Besides, why we want anything more than 35 psi to double the load carrying capability at the maximum load of 1,764 lbs. / 1,709 lbs. and in fact we only need ~900 lbs. load carrying for each tire?
And yes, the range of tire pressures are to get an optimal contact patch but the factory recommended tire pressure, especially the "one-size-fits-all" approach in the US, may not work for non-OE tires.