Packard Forum Index » Post-War (1946-54)

I know there have been a lot of posts about tires, but I wanted to get some more opinions before I swap to radials. I am currently running a set of Commander 4-ply polyester cord tubeless bias ply H78-15 Load Range B (1770lbs @ 32psi) with a 28-inch diameter face on my 1954 Packard Clipper Super. They have a 3-inch wide whitewall and, according to my local tire dealer, the sidewall code indicates they are 15 years old. I am running the tire pressure at 24psi cold inflation pressure per my 1954 owner's manual.

I am concerned that, due to age, these tires may be prone to failure and I don't want to have a blowout at 65mph.

I would love to have a set of radial wide whites, but at around $1000 bucks for a new set, I am tempted to go narrow whitewall or black sidewall just to keep her rolling nicely.
I suspect the proper size radial may be 225/75R15 or 235/75R15 but I am having a hard time deciphering the tire size conversion charts.

Is there a definitive source for an easy-to-read conversion chart? Do you think I currently have a safety issue? Would you go black wall or should I save up my coins for the wide whites which do look nice on the car?

Thanks for all your help again!

Here is one conversion chart that may be of help.widewhitetires.com/CrossReference.html

Hello Steve:

Take a look at the bottom part of this page from the Diamondback catalogue, (page 17):dbtires.com/2011_catalog/hi/17.htm While they advertise them for "for pre-1948 Luxury cars" (read CCCA cars) they should work for your 1954.

These tires are radials, but built in bias-ply sizing. I am putting them on my 1941 120 business coupe. Notice the absense of radial sizing e.g. 225/75R15. Therefore, you get the proper aspect ratio of a bias-ply tire.

Give Diamondback a toll-free call. Even if you do not buy from them they will share a wealth of sizing information with you.

A bit of advice that's probably irrelevant now since you're going to retire, but when the tires on the car are so different from what was originally specified (e.g, letter-series), you'd be better advised to take inflation pressure guidance from the tire sidewall info or tire maker rather than the Packard owner's manual.

I just went through this on my '54 Clipper Deluxe. If you want 3" whitewalls in the closest size from Diamondback you are going to end up with Fury 225 75 15 tires. They aren't as tall, so your speedo will be about 10% off. The tires look and handle great - no more squeals when cornering, much better handling.

Thanks '54 Clipper' in Ellicott. Yes, Coker rep translated my current bias ply H78-15 into the size you gave me..
225/75R15. Thanks for the feedback on the DB tires.