Radial Tire Pressure

CT Jack

CT Jack

Well-known member
I just received my first set of American Classic 19" radial tires and would like to know what tire pressure has been found to be the best to use.
Thanks
 
I have a heavy 30 Fordor with a trunk full of tools and spare parts in the rear. I have the American Classic radial tires run 50 psi in the rear and 45 in the front. Modern tires, including the American Classic radials, can take 200 psi, if they have not been damaged, for instance by running them flat.

The trick is to go for a drive and then put your hands on the sidewalls. They should be warm to the touch but not hot. If they are hot the air pressure is too low. The tires can be damaged if the pressure is too low. The 35 psi comes from the bias ply tires which are stiffer and can be run at a lower pressure. The handling is better with the higher pressure.
 
Thanks for the responses. I have a Coupe which is much lighter than a Fordor loaded with tools. However, this being my 1st experience with radials on an "A" I plan on trying different pressures to see how they affect handling.
 
the tires are probably marked on the sidewalls, with the max recommended, I wouldn't exceed that. I have modern radials on my A pickup, and run 25 in the rears and 32-34 in the fronts. The rear of an empty pickup is quite light.
 
The radials show a maximum pressure of 35 but in my experience it is not enough. For one thing, the tires run too hot. Plus the handling is not as good as you would expect. There is probably a liability issue with running higher pressure so you do it at your own risk.
 
Little high on the tire pressure sure beats low. No matter what vehicle, from semi to bicycle.
 
I have 550R19 Stahl Sport Radials by Coker. Sidewall states MAX 44PSI. I run them at 40 on my '31 CCPU.
 
Never heard of the tire heat trick before, good idea! I just run them a while and see where the wear is. In the center, too hard! The outer edges, too soft! The Radial tire must not be overinflated more than a few lbs. It breaks the attachment of the rubber to the wire and you have a pregnant tire, complete with a bubble on the tread. Don't ask me how I know!
Terry
 
nkaminar said:
The trick is to go for a drive and then put your hands on the sidewalls. They should be warm to the touch but not hot. If they are hot the air pressure is too low. The tires can be damaged if the pressure is too low. The 35 psi comes from the bias ply tires which are stiffer and can be run at a lower pressure. The handling is better with the higher pressure.
Click to expand...

What should the temperature be if using an infared thermometer? Warm to the touch can mean different things to different people.
 
nkaminar said:
The radials show a maximum pressure of 35 but in my experience it is not enough. For one thing, the tires run too hot. Plus the handling is not as good as you would expect. There is probably a liability issue with running higher pressure so you do it at your own risk.
Click to expand...

I do run about 5 lbs. over the rated max pressure on my trailer, for the reason stated above.
 
Warm depends on the ambient temperature too. It was 113 degrees here in Mesa, Arizona yesterday. At home, with an ambient temperature of about 85, the tires will feel 90 to 100 by touch. Most people find it uncomfortable to touch something that is 140 to 150 so that would feel hot. The higher temperature indicates the tire sidewalls are flexing a lot.
 
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