AMuzi:

Corvair

The Corvair had a Front/Rear weight difference that
definitely warranted the big difference between
recommended front and rear cold tire pressures.

The cars I'm talking about are somewhere in between
that extreme, and the other: rear- and all-wheel drive
sports sedans with almost no(less than 55/45) front-rear
weight bias. The last time I checked, a typical BMW
F/R weight split is like 51/49%. Yet recommended
front/rear pressures differ by 5psi.

My Honda Accord, for example, is F/R: 54/46% axle
weight split. Some 'econoboxes' venture toward 60/40,
yet for the Accord and those cars, a single pressure
figure, for all tires, is specified on the door frame placard.