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

The biggest offenders for flat-spotting were bias ply tires during the time they used Rayon cord. Nylon and later polyester cord pretty much minimized or eliminated most of that. Many savy car owners and tire shops recommend extra inflation pressures during the times the car is laid up and I do that to both the Packards during the winter lay-up.

Since I've been castigated for running my tires at "too high of pressure" (I still think it's better than low pressure), let me throw one more obscene idea/question/comment out there:
The idea of having to buy new tires based on age I think has more to do with tubeless tires -- radials -- than bias-ply tires with tubes. I'm sure you'll all think I've got some kind of death wish, since the tires (bias ply with tubes) that I run with 40psi at 75mph are probably 40 years old.

I have a new set in my garage, but I'm sure that I'll be completely dissatisfied with the performance compared with the older tires, so I haven't put them on yet. I hear too many stories of how the new tires just don't stand up to the older tires in quality.

By the way, I highly recommend buying tubes from your local Firestone (or whatever dealer near you) store, as opposed to the paper-thin ones you get from classic car specialty tire sellers. Not only are they much better and thicker tubes, but they are less expensive as well.

West - just to be clear, I agree that it's probably better to run higher rather than lower pressure on bias ply - my concern was about running much higher than the tire's maximum rating.

It's an interesting question you raise. It's been said fairly often that radials should be replaced at about 8 years age regardless of tread wear or use. Now whether that's the tire makers recommendation to promote new sales, or truly a safety issue is unknown to me. And there are many who say that bias ply have a far longer safe lifespan and for that reason are often the better choice for collector cars that don't accumulate a lot of miles.

Ah, to be able to separate murky myth from fact.....

West - just to be clear, I agree that it's probably better to run higher rather than lower pressure on bias ply - my concern was about running so much higher than the tire's maximum rating.

It's an interesting question you raise. It's been said fairly often that radials should be replaced at about 8 years age regardless of tread wear or use. Now whether that's the tire makers recommendation to promote new sales, or truly a safety issue is unknown to me. And there are many who say that bias ply have a far longer safe lifespan and for that reason are often the better choice for collector cars that don't accumulate a lot of miles.

Ah, to be able to separate murky myth from fact.....

My 55 Patrician had radials on it in the 70's. I put sears white walls on it. It helped with the height. The radials were low and I would scrape the frame going into my dads garage.

Are the heights better now on the radials?

All,

I have been following this thread with interest since I had purchases new tires last year for my car.

So I had asked Universal Tire this question
Quote:Quote:

Are the heights better now on the radials?

I guess it depends on what series you purchase, series 75 sit a bit higher than Series 70, and so on. Take a look at the inflated diameters on the Goodyear/Kelsey chart I posted a few post previously and you'll see the differences.

I wasn't trying to be hard on the 40 psi in those Firestones, or sarcastic or anything like. As I mentioned my concern is accelerated suspension wear. Except that high pressures are also more subject to hydroplaning and forget about snow. In the old days I heard a lot of complaints about Packards in the snow. Maybe the tires were inflated too high. I drove a V-12 back from Buck Hill Falls PA in a blizzard and didn't think it handled bad at all. I was asked to drive it because the owner was afraid to use his trailer.

I checked and those Firestones are rated 1600 lbs per tire at 40psi. So for a 3 ton car 40 psi is the pressure to use and anything heavier needs a higher load rated tire. I'll wager that if you asked Firestone for a load/pressure chart for those tires it would be pretty close to the Packard specs from 1940.

As regards storage, I would put the car up on stands under the frame and unload the suspension. Those springs sag too easily. It doesn't have to be wheels off the ground, only unloaded.

I'll see if I can find a general passenger car load pressure chart and put it up. I have them for the military and they read: Axle loading X lbs - Tire pressure Y psi for Load Range Z

Re; age of tyres:
I'll have to side with West peterson post #42 para #1.

I have an 89 Caprice that ran OEM FACTORY ASSEMBLY LINE tires from 1989 thru 2011. Only reason i replaced them is that they were worn out. I won't bother to list many other similar examples i've experienced over the years. Some tires as old as 30 to 40 years old.

WE all have something called EYES in our head and EARS on the side of our heads. I tend to use mine.

Even when a tire is showing some superficial cracking they can still run very well. OF course there is a limit to that. I tend to inspect my tires on all vehicles every oil change and look at them very close.

Most of the tire trouble i've had over the years has been with very high end premium quality brand name tires. The cheaper offerings (even one size larger NOT SMALLER!!!) are usualy much lighter tire, require much less weight to balance and run just fine. Don;t last as long maybe for wear that's true.

Dear Tom(Packard 31):

The answer you got is a little hard to understand. What are they saying?:

a) The sidewall notes show the maximum load capacity at the maximum inflation pressure. Thus, for lighter loads a lower tire pressure is sufficient. Usually that is published in a table that can be used for a given vehicle.

For example, a 4200 pound Packard is pushing around 1250 per axle including two passengers and excluding weight distribution.

b) I have no idea what they are talking about as regards old cars being "exempt" (from the laws of physics).

c) If the vehicle weighs less than the maximum load capacity for the tires then of course you can reduce the pressure. Increasing pressure increases the load capacity of the tire, but if for a given pressure you are at the load capacity being carried, then higher pressure is not required. That's what a pressure table does.

For example, 1600 lbs at 40 psi, 1300 lbs at 35 psi, 1000 lbs at 30 psi. See if you can get a table from the manufacturer for your tires or a table for the load rating of your tires. You can always go to a trailer place and get a tire pressure table for trailers. Trailers use those tables.

Since your car has snap rings these are important considerations.

The Packard spec of 40 psi is for a Six ply 19 X 7.00 tire manufactured in 1931. A tire manufactured today may very well handle the same load at a lower pressure. You want that because of those snap rings.

If your tires are 4 ply, they will have lower maximum pressures, but with those old snap rings 40 psi is pretty scary.

Hope this helps