I am experimenting with tyre pressures on my model a pickup to get a better ride. At the moment my tyres are running 25 psi and the ride is very harsh . Just wonder what pressures work best for others . The truck is very light so wonder how low I could get away with . Just finished my new mascot .
If they're bias-ply tires, you can go lower. Just don't drop pressure to the point that the tire looks low. Radials are the ones that do badly if pressures get too low. But keep in mind that if the suspension is too stiff for the vehicle weight, this may not help much. You might consider removing one or two leafs out of your springs if they're still stock.
I had 29 psi in the 560-15 s and 20 psi in the L78 15s on my 34 Plymouth- my 56 Chevy runs perfectly on 710-15s on 22 psi. My Riviera likes 26ish--- just play around, it seems every car has it´s own combination
The tyres are firestone deluxe champions and are a bias ply . I dropped the pressure to 10 psi to see what they look like . It made no difference to the shape of the tyre .
That may be caused by the tire plys actually. We try to run 4 ply tires for obvious reasons. But it is common for us to get stuck with 6 or 8 ply tires. A lot of how you set your tire pressure depends on the tire itself. One thing to keep in mind is that if you get the pressure too low the tires will have a tendency to spin on the rim (that would be the outside hoop not the entire wheel for you correct word idiots). Here is an interesting thought or bit of historical data. The Ford motor company built a little SUV thingamabob called an Explorer in the '90s. They were having one helluva problem with the tires letting go which eventually cut into the profits of the company that made the original equipment tires on the little POS. After some serious testing and investigation it was discovered that the Ford Motor Company was having a problem with ride and cured it by running the tires low. The radials heated up and let go. Moral to the story? Tires are not a suspension component if it rides too rough work with the springs to get it right.
If the ride is harsh its more likely to be a suspension issue , post a pic of the front and rear end if there is a problem there someone will spot it , I would stab a blind guess that the front spring it to long and sitting on top of the axle doing nothing . If the shackles cant flex the spring will be redundant and the ride will be harsh .
On my 32 roadster which is very light I run 18-20psi front and around 15psi rear. Mine rides harsh also because we need to do rear spring work to soften the ride but the lower pressure helps to cushion the ride. I am running bias ply all round.
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