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

If you notice the GM spec I put up from the 60's specifies additional 4 psi cold pressure for speeds above 75 mph.

That is a lot different than nearly doubling the tire pressure to the maximum on the sidewall.

The tires on my modern car are not rated for sustained speeds above 80 mph so I won't be increasing pressures anytime soon. I also wouldn't drive any Packard like that either, but the bottom line is increased suspension wear because running higher than necessary tire pressures is mitigating the first tier in the cars suspension - tires.

I had an old Ford that I used to drive like a maniac. It slid beautifully and I didn't run excessive tire pressures in it. But it was really good in the snow and I'm sure would not have done as well with over inflated tires. Once I raced an old Chrysler New Yorker up a 5 mile long hill and he blew his engine. I had the Ford in Low with my foot on the floorboard and the power steering pump overrunning and screeching. I was doing around 65 mph when the Chrysler started blowing smoke.

I have a set of genuine Firestone 7.00 x 15 "Gum Dipped" tires on my 47 Custom Clipper that were installed, new, in the mid-1980s. They are in great shape, and the wide white walls are still white. The thread is still full; although, the car has probably been driven less than 5,000 miles since they were installed. I inflate them to 30 p.s.i. They are smooth, steer straight, ride well, and brake evenly. The spare has not been on the ground. I think this answers the question about the quality of the old bias ply tires as compared to the ones that are now being made.

I know the time is fast approaching when they should be replaced, and I will probably go with a set of Diamondback radials.

(o{}o)

JW, not to put too fine a point on it,
But
Change them tires!
Please.

Here is a history of tire pressures for Packard using selected series:

5th-7th................40 psi
11th.....Su 8..........36-40
14th.....V-12...........40
15th....Su8 & 12.......28F 32R......6 ply......1505, 1508
17th....Su8 & 12.......28F 32R......6 ply......1705, 1708
18th....Su8 127".......26F 28R
..............148".........28F 32R
22nd....Cu8 & Su8.....26
..........Std..............28
24th-55................24

The 5th-7th series are snap ring wheels and we used to set them to 32psi because of those old rims.

You can fill pits, but the metal is still old and fatigued. If the gauge reads low you don't want to die.

As soon as Packard went to independent front suspension they dropped the pressures.

Except for the snap ring problem, suspension wear is a limiting factor. Especially with old sagging springs.

Radials may specify higher pressures, but they need it.
If the maximum specified by the radial is 45 psi then 75-80% of the maximum is 34-36 psi. 32 psi is very popular with modern cars.

Randy, thanks. It is not the tires I have concerns about, but the tubes. It will only get driven around town at low speeds until new tires are fitted.

JW, I'm beginning to have the same concerns about the tires (7:00-17 x 6-ply rated) and tubes on my 34 Eight. I tour rather regularly with this car, close to 1000 miles in each of the last few years, and the tires/tubes are now just about 20 years old and about 18,000 miles. Lots of tread remaining, and before last year's extended tour I gave them a thorough almost microscopic exterior examination and found no issues, they actually looked pretty much like they did when I installed them. But who knows what lurks inside? One reason I've been hesitant to retire is the considerable amount of negative comment about the reliability of the current metal valve-stemmed tubes failing at the valve stem insert. 1934 was the last year for metal valve stems and I really want to keep the original appearance. I know I can get the dummy "slip-over" thingies that simulate the look of metal valve stems and I may have to go that route. As to the tires themselves, this is my 2nd set of Lesters and they have been satisfactory in the extreme though I do wish the whitewall width were just a bit closer to original.

Just to get back on-topic, they are rated for a maximum load of 1465 lbs at 36 psi, so x4 = 5860 lbs. The car's dry weight is 4540 lb. so I feel comfortable with inflation pressures a bit less than max; I use a cold pressure of 34 psi. What little tread wear there is is very uniform side to side. For comparison, on the 56 Carib convertible I have Goodyear Super Cushion polyester/steel corded P235/75 R15s from Kelsey tire. They are rated at 2028 lbs each at 34 psi or 8112 lbs. With a car dry weight of about 5100 lbs I feel comfortable and get a nice ride with about 30 psi. These Super Cushions (pix below if I can find it) have proven to be a very fine tire, my only complaint is that with the agressive tread pattern they aren't the quietest tire around. Being a bit (understatement?) of a purist, I really didn't want radials on this car so I bought a set of 8:00-15 General 90s (which was an original tire offering by Packard) from Kelsey Tire. I have to give a plug to Kelsey Tire here, those Generals wore very rapidly and when when I demounted one and sent it back to Kelsey at his cost for examination, he offered me a set of 4 of these Goodyears at a truly exceptional price and I couldn't resist. Do they actually handle better than the bias ply tires - a bit but nothing really dramatic.

Attach file:

---

  (115.61 KB)


  (76.58 KB)

Quote:

I strongly second the sentiment. Just went thru this on my 99 Ranger PU. Truck has very low mostly in town use so still had original tires and less than 18k on the odometer.

One tire recently developed a slow leak. Thinking I had picked up a nail, took it in. No nail but the shop found the tires had all developed cracks -- Very fine and could barely be seen on the outside. The leaking tire was most severe and crack was deep. The others were well on their way though. A good road trip and I have no doubt it would have been a very interesting experience.

Being in the new tire thinking about it stage for my 56, with O_D's info am now debating the Kelsey offering vs the Diamondback offering. I know the car barely leaves the driveway so probably a total waste but anyway-- Out of curiosity, how do radials do on sitting. I know from experience bias tires tend to develop flat spots. Have not had radials sit so are they prone to the same issue.

On the tire purchase, Neither place appears to have a west coast outlet so that's a toss. Minimal spec difference. Both claim to be US made, one Goodyear & DB in one series says Cooper, other DB offering in wide white brand is not mentioned. Higher price on the Kelseys.

O_D has good reviews for the Kelsey and others have had good reviews for the DBs. Comments ??

I didn't like the way my 53 Cavalier road or handled with the Coker Bias Ply 3"WW 820x15's that were on it. I just installed a set of Coker American Classics P235-75R-15s 1.6"WW (35psig tire pressure, $165 each) what a difference (night and day). I know these aren't original to the car but I really enjoy the way the car rides and handles now. My wife always felt uneasy because of the way the car felt with the bias tires. She loves riding in it now. That alone was worth it! We tend to drive the car a lot more now.

Thanks,
Dennis

HH56.
The radials will develope flat spots too. I have 2 cars and 2 trucks, actualy 3 trucks. a 56, two 88's, an 89 and a 2001. All have radials. If any one of them tend to set for more than 2 weeks at a time (once in whaile as long as 3 months) the radials will tend to have slight thump to them. Nothing drastic but noticable. The thump will usually go away after about 20 to 40 miles of driving.

On the other hand i bought a set of wheels and radials about 10 years ago from a junk yard. No telling how long the car had set. I'm guesing YEARS and the tires were premium 235 75R 15 brand. Those damned things shake the fillings out of anyones teeth at 25 mph. It was low speed vehicle (Jeep) used mostly on the road. It took about 500 miles and hot summer weather for them to smooth out with no noticeable trace of any problem at all.