Local high school has two Corvair as project vehicles. Got me to thinking (bad signš), Corvairs were equipped with bias ply tire and required different front and rear tire pressures F24, R30.
Google AI recommends 10 PSI difference, 22/32 if using radials. Seems track testing would be required. No consensus on a Corvair forum.
Any comments?
It may depend on the model year. The manual for the first-generation Corvair, with swing axles, called for 26-30 psi in the rear (depending on anticipated load) and only 15 psi in the front. The later Corvairs (beginning in '65, I thinkā¦) with independent trailing arms and semi-trailing arms may have had somewhat different inflation specs.
I dunno, I never got the memo on lower front pressure when I had my corvair. I donāt think 15# is enough to keep the tires sealed though. As far as I can remember I Al alway ran 32 front and back but never took it out of town. I think a 10# difference would be all I would do. A classmate did manage to flip a new one back in 60 or 61, but not the brightest bulb. On snow days weād run out through snow banks just for fun. Never got stuck.
Iām pretty sure I remember Chris covering this many times before, I am sure he will chime in here at some pointā¦
40/60 front to rear weight distribution so front should be lower. 22+32 = 54 psi
40% of 54 is 22 (rounded to no decimal places)
60% of 54 is 32 (again rounded)
So I would agree with AI saying 22/32 just on that aloneā¦ But the 1965 Corvair has a far superior suspension than the 61 to 64 models. I have seen them at the race track and on autocross courses. They can be wicked fast!
I am curious why no one thought to question Ralph Nader about thisā¦ Heās still alive at 91 and I bet his mind is as sharp as it ever was; was it; is it? 
Ralph Nader famously criticized the Chevrolet Corvair in his 1965 book Unsafe at Any Speed, calling it the āone-car accidentā due to its unconventional rear-engine design, swing-axle rear suspension, and lack of a front anti-sway bar. He argued these elements, particularly the suspension, could lead to dangerous handling issues like oversteer and rollovers, especially under improper tire pressure or when the vehicle was heavily loaded.
These were his primary concernsā¦
Uncommunicated Tire Pressure: The swing-axle system required very precise tire pressure settings, which were not clearly communicated to owners, leading to instability.
Swing-Axle Suspension: The independent rear suspension allowed the wheels to articulate at extreme angles, which could lead to a loss of traction or the outer rear wheel tucking under the car, potentially causing a rollover.
Lack of Anti-Sway Bar: Without a front stabilizer bar, the car was more prone to oversteering, making it difficult to control during sudden maneuvers.
There was a whole lot more that he did not likeā¦ But he thought it made a great ācubeā after being crushedā¦ 
Yeah the kid that rolled it had a car full from our confirmation class, so fully loaded. 50 some years later he is a clothing salesman, so not the brightest.
That description of āissuesā Nader had with the Corvair is matched by the VW Beetle, and many other rear engined cars from the French and Italians. Swing axles were under Mercedes cars as well. It was a common design used in the late 50s and early 60s.
As for the ācommunicatedā tire pressure issueā¦. That is a RTFM problem ALL carmakers and buyers have.
I have no love lost for GM but Nader targeted them because they were Goliath and Nader was David. Makes for the NYT #1 books list. Plus GM had the deepest pockets for lawsuits that would cite the book as evidence.
What I said for my corvair tire pressure was the same for my VW. Pressure was the same all around with no problems.
Does the high school have a road course? I donāt believe tire pressure is critical for a car parked inside a workshop. 40 psi would be satisfactory to prevent flat spots.
Corvair tire pressure has been discussed dozens of times before Chris joined the forum, by the same people, over and over again.
Didnāt you work developing suspension systems that went into GM cars?
Just because you like a vehicle(s) doesnāt mean you like the companyā¦ lol
Yes, I did. I worked for Delco Products Division of GM. GM then sold us off and created Delphi. Delphi was supposed to be able to compete for business with every manufacturer but we still smelled like GM (as one Ford engineer stated). Delphi filed for bankruptcy in 2005 primarily because we were mismanaged by the (incompetent) ex-GM execs they put in place.
I quit in 2006 so I could grab my pension buyout and put it in my own IRA because I did not trust Delphi not to toss their pension into the Pension Benefit Guarantee Corp (a Govt. run insurance company) that would have greatly reduced my benefits.
When GM itself went into bankruptcy in 2009 (?) one of the bigger bondholders was Delphi. Bondholders normally would be first in line for compensation in a bankruptcy but the Govt. decided otherwise and Delphi (whose pension was a large bondholder) was forced to dump the pension into the PBGC screwing friends and family that stayed. And then my old division was sold to the Chinese.
I did OK working for a forklift company for a few years and then retiring early - something I would not have been able to do had I stayed. Sooooā¦ No love lost for GM.
It was clearly stated in the owners manual, and pointed to in many contemporary automotive periodicals.
Thatās the equivalent of running 44psi in all four tires of a recent car requiring 32-33 psi cold.
Why do that?
See folks: Challenging, politely mind you, decisions like the above regarding car maintenance, is what got me in trouble here in the first place. I just want to know why some people decide to so things the way they, and not the manufacturers, think they oughta be done.
Didnāt the Big Three usually under state the tire pressure on their full size cars so that it gave a smoother, more comfortable ride? Working at a Ford Dealership in the late '60s we performed āPanicā brake stops and found the factory recommended pressure left tire marks with darker marks on the pavement from the outside of the tires and stopping distances were longer than when we increased the pressure a few pounds. Granted it was far from scientific, but there had to be something to itā¦
In some cases perhaps.
But the bias ply construction of tires of that period required relatively lower cold spec pressures(24-28psi) than did radials(32-36), to carry the same gross loads.
My Bethlehem Steel pension ended up in PBGC. I only had 12 years in the defined benefit retirement program and got my full benefit. Higher paid salaried employees may have lost compensation since PBGC has an upper limit on payout. Since those were management, maybe itās just desserts. They stopped the defined benefits program after my 12 years but a lot of the people I worked with had many more years in the program. We all got a 401K after that.
My tablet battery was dead.
They are first Gen Corvairs.
I think MustangMan got it.
To simplify, and I guess this would apply to many cars the had bias ply tires as OEM, go by pressures listed in owners manual for bias ply tires, which my guess would be too low for radials. Over on a FB page there are people that claim radials on a car that came with bias ply tires will cause faster wear to steering and suspension components due to better āgripā on the road. I donāt believe it.
According to Tom McCahill, yes, he recommended higher inflation, he also recommended going up a weight for the dinosaur oil, ie EOM, 20, he said 30 for summer use.
Yep, I like my blue oval cars, that does not mean I approved of Henryās anti-Semitic views.