Tire pressure on 48 Ford

[48fordconv]

I have a 48 Ford Conv. with Daimond Back 205R75-16 Tires. What is the correct air pressure? Thanks

[V8 Bob]

Originally Posted by Steve-Maine

I have a 48 Ford Conv. with Daimond Back 205R75-16 Tires. What is the correct air pressure? Thanks

The correct pressure is what that tire was designed for, and should be visible on the back side, along with the D.O.T. info,....or contact DB to be sure. Normally most radials run at least 35 psi.

[Kube]

Originally Posted by V8 Bob

The correct pressure is what that tire was designed for, and should be visible on the back side, along with the D.O.T. info,....or contact DB to be sure. Normally most radials run at least 35 psi.

It isn't quite this simple.
The information molded on the tire is the maximum that particular tire can be safely inflated to. It has little to nothing to do with the recommended tire pressure for any specific vehicles application.
The specific (vehicle) application determines the pressure. Things like ride and handling and SAFETY are major factors car manufacturers use to determine correct pressure.
Installing radials on a car that was not designed for them leaves "proper pressure" in the oxymoron category. There is no "proper pressure" for this application.
Trail and error will determine what works best.

[V8 Bob]

Originally Posted by Kube

It isn't quite this simple.
The information molded on the tire is the maximum that particular tire can be safely inflated to. It has little to nothing to do with the recommended tire pressure for any specific vehicles application.
The specific (vehicle) application determines the pressure. Things like ride and handling and SAFETY are major factors car manufacturers use to determine correct pressure.
Installing radials on a car that was not designed for them leaves "proper pressure" in the oxymoron category. There is no "proper pressure" for this application.
Trail and error will determine what works best.

Kube. with all due respect, radial tires should not be "adjusted" to vehicle or axle weights, that was common with bias/belted tires. ( I used to think and do the same, until I learned more about them) Radials can be damaged if under inflated, unlike bias/belted. Best to contact the supplier (in this case DB) and get the correct inflation info, but generally 35 psi is about the lowest psi.

[Kube]

Originally Posted by V8 Bob

Kube. with all due respect, radial tires should not be "adjusted" to vehicle or axle weights, that was common with bias/belted tires. ( I used to think and do the same, until I learned more about them) Radials can be damaged if under inflated, unlike bias/belted. Best to contact the supplier (in this case DB) and get the correct inflation info, but generally 35 psi is about the lowest psi.

And, with due respect, I disagree.
Cars are designed with a particular tire in mind. That tire has certain characteristics that meld with the vehicle as designed.
The E series tires on my pick up state clearly on the side maximum 65psi. The manual states 50psi.
The front tires on my Porsche state max 45psi, manual says 32. Rear tires (different series and size) on the same car state max of 45, manual says 28.
Can you imagine the loss of handling if I inflate any of the above examples to the tire max?

[V8 Bob]

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Kube,
I also never run the max psi stated on the radials, but closer to it than with bias/belted tires, generally 32-35 minimum. In many cases the suggested OE psi is more for ride comfort than tire mileage. My point was a normal radial tire pressure is going to probably be higher than the bias/belted tire pressure it replaces, and consulting the manufacturer/supplier for the correct pressure is the best advice.
An example-My '51 Ford stock 670X15 bias tire pressures are 24 Frt. and 21 rear, but the 205/75X15 DB replacement radial recommended pressure is 35.

[hardtimes]

Originally Posted by Steve-Maine

I have a 48 Ford Conv. with Daimond Back 205R75-16 Tires. What is the correct air pressure? Thanks

Hey Steve,
Yeah, like nearly everything else in life there will be differing opinions on your question. However, I'd start with V8 Bobs' information and go from there. Regarding tire safety....generally a few pounds OVERinflation is more better than a few lbs underinflation . Of course everything in life has exceptions. But, with a few lbs over , for your case, may show as center tire wear as opposed to underinflate which can/will show as possible destruction of tire (heat/breakdown/blowout).

[Marv]

I had a 47 Ford coupe with radials and i ran 35 lb of air in all 4 tires. It handled better than it ever did with bias ply tires and the tires wore flat like they should. An over inflated tire will wear in the middle. Marv

[woodiewagon46]

Steve, why not give Diamondback a call, I'm running Kokers on my '46, (never again) and they recommend 35psi.

[Vic Piano]

I have radial tires on most of our antique cars/trucks, both 15 & 16 inch and I generally run 40 psi in all the radials, tube & tubeless. I've logged literally thousands of miles with our vehicles and never had a problem related to over inflation of the radials, in fact, I find that the cars & trucks are easier to steer and the overall ride and handling are significantly improved with the radials at 40 psi. In most cases actual road driving experience is the best way to determine what pressure you want to run with.

[Talkwrench]

You didnt say if they are whitewalls.. Generally the tyre they use for them have a max of 35. I have 205x75x15 I run them up to 35 no probs. keep it on the high side, you'll be fine.