what's the significance of max pressure rating?
 

Two tires have almost identical specs (size, treadwear, speed rating, load rating) but one has a max pressure rating of 44psi and the other 35psi. What can I conclude from this difference?

Thanks,
Sixto
91 300SE
87 300SDL

Interesting. Nothing much I guess, just one tire can handle heat and pressure better then the other I guess. CAn you share what brand and tire and size they are?

I don't recall exactly what tires I was comparing. I think one of the comparisons was the Goodyear GT2 and Conquista which have different speed ratings but similar load ratings. I was looking at specs published at tirerack.com. These are tires for my minivan, not my MBs.
Sixto
91 300SE
87 300SDL

I clipped an article from an automotive trade magazine that discussed tire pressures.

It speaks to the confusion regarding what is the proper tire pressure - what is stamped on the tires, or what the decal inside of the door or on the 'B' pillar says. Following is an excerpt:

"The Rubber Manufacturers Association told federal regulators that those pressures stamped on the sidewalls of tires should be eliminated. They are, simply, the maximum inflation pressure for the tire but are a "source of misinformation and confusion" for consumers, the group said.

Donald Shea, RMA president, went on to explain that "the current listing (on the sidewall) of the maximum pressure on tires is not the recommended normal inflation pressure."

Rather, you should use the tire pressure recommendations found on your vehicle's decal - also in the owner's manual for your vehicle- to properly inflate your tires. These figures are determined specifically for your vehicle and take into account your vehicle's weight, handling characteristics, etc."