Tire pressure

[Chas Henderson #28127]

I was checking my air pressure on my 71sb today. I was wondering what the proper cold air pressure would be for my goodyear Eagle GT radials? I know that the recommended pressure is 24lb for the original tires, but I do not recall seeing pressure ratings anywhere posted for radials on an older car. I have been keeping them aired up from 30-32lbs. Any thoughts on what the correct air pressure is?

Thanks,

Chasman

[Mike M.]

Re: Tire pressure

somewhere on the goodyears there ought to be a recommended pressure. i'd guess its 35 psi. mike

[Rick A.]

Re: Tire pressure

Chas,

the Goodyear Regatta radials that I run on my 1963 Z06 (when I drive her) are kept at 32 pounds when cold

[joe utz]

Re: Tire pressure

I'm not sure about a 71SB but I just bought a set of Coker Classics for my 1960 and there was a sticker on the tires instructing me to inflate to 35psi.
Joe

[Terry M.]

Re: Tire pressure

The pressure that is marked on the sidewall of the tire is the MAXIMUM inflation pressure, and should be used only for seating the bead - not for operating the tire.
Tire pressure specifications can be found on sites such as Tire Rack. The inflation pressure assigned for maximum load ratings for P-metric tires is 35 psi. That does not mean that is the best pressure for handling, only the optimum for maximum load. Use it as a starting point, and experiment for the pressure that you find makes the best compromise for your driving style.




Tire pressure details

[Duke W.]

Re: Tire pressure

What carries the vehicle load? Answer: Air pressure. The higher the tire air pressure the higher the tires' load capacity up to its maximum placarded load and cold pressure.

Since typical OE and replacement size tires have relatively high load capacity for the Corvette's gross weight, relatively low pressures are acceptable, but higher pressure will provide better tracking, crisper steering response, better fuel economy, and greater tire life, but may increase ride harshness. Most importantly, higher pressures keep the tire cooler, so there is more safetly margin to prevent a thermally induced structural failure, especially at high freeway cruising speeds in hot weather.

My recommendation for vintage Corvettes would be to consider the OE recommended pressures as ABSOLUTE MINIMUMS. For original or modern replacement sizes I recommend 32 cold as a starting points on C2/3 SBs. BBs and solid axle models can benefit from 2-4 pounds front pressure bias because they are more front heavy. From this base you can experiment with settings that give you the best ride/handling compromise within the range of tire placarded maximum cold pressure and the OE recommendation.

Tire pressure was a big factor in the recent Ford Explorer fiasco. Ford pointed the finger at Firestone and said tire quality was substandard. They were correct. Firestone pointed the finger at Ford and said their pressure recommendation was too low for vehicle weight. Also a correct statement! Ford established recommended tire pressure at an absolute minimum to reduce tire grip in order to mitigate the Explorers' tendency to roll. Add too low a minimum pressure to minimum specification tires that were not built to par, plus typical owner lack of basic vehicle maintenance such as tire pressure and the safety margin was near zero to negative!

The maximum specified pressure for low or no speed rated P-metric radials is 35 psi. European code tires start at 36 and both typically have higher maximum pressures as speed rating goes up. Many Z-rated tires are now carry a maximum cold pressure rating of 51 psi, but 44 is more common.

Duke

[kelly theaker]

Re: Tire pressure

on G/Y tires you will find max tire rating on the tire right next to the bead of the rim / hot stamped in - take a look .this may be a standard info setting?

[John H.]

Re: Tire pressure

See Terry's post above - that's the absolute MAX inflation pressure, not the recommended vehicle-specific operating pressure.

[Chas Henderson #28127]

Re: Tire pressure

Thanks for all the imfo. The tires are rated at max 44lbs. I guess I will keep her at 32lbs.

Chasman