The info tag on the driver door is not readable for air pressure. What would the air pressure be for 1984 Trans AM? 35 lbs?

 

That sticker only applied to the original tires (probably long gone). Instead, just look at the sidewalls and there is a pressure rating on them. 35 psi is a pretty safe bet though. That is the minimum you will find.

 

The tires don't have any idea what car they're holding up. Pressure is indicated for the car and it's weight and characteristics. Pretty sure factory rating in 30 pounds cold for all our cars. with 35 you might save a tad on mileage but will suffer in ride, wear, and handling. Just my humble opinion...

 

Modern tires might not want the same exact pressures as factory tires, but 30-35 PSI is probably the zone you will end up in for a street tire. I found 32 PSI all around to be pretty good for whatever used tires came on my wheels, but you should experiment to see what works best with your setup.

 

As long as the replacement tire is the same size and load rating as the original tire (which it most likely is), then the recommended air pressure on the door tag would still apply. The max inflation pressure on the outside of the tire is going to be much too high and result in a poor ride and uneven tread wear. Each tire manufacturer produces a load rating/inflation pressure chart for their tires and the auto manufacturer uses that information to determine the recommended inflation pressure based on the maximum GVWR of each axle. A replacement tire of the same category (Passenger in this case) are all going to have very similar load/pressure ratings. From what I have seen on these cars, the recommended cold inflation pressure is 30psi. Every other vehicle I have come across with Passenger (P) rated tires, the door sticker has recommended pressures somewhere in the 30-35psi range.

Now, this completely changes if you are going with a different classification of tire and/or load rating. For example, most 1/2 ton full size pickup trucks come with P-series tires, but if you replace them with an LT-series (Light Truck) tire, their pressure/load chart is completely different than the P-series and you would need to run more air pressure to achieve the same tire load rating. An LT tire would need about 45psi to achieve the same load rating as a P tire at 35psi. I know that's not the example we are talking about here, but that is when you would disregard the door sticker and use the tire manufacturer's pressure/load chart (but still not the max inflation pressure listed on the sidewall of the tire).

 

This afternoon, I set the pressure at 32 lbs. Remember when before radial tires, fibreglas tires were 26 front & 28 rear on my '70 Malibu