| Moderated by: Greg Fletcher | ||
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Frank Schwartz Guest
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The service manual and the owners manual specify 24 pounds of pressure for the tires. Is this still correct???? |
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SportsRodder Member
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Best to go with the recomdendations of the time manufacturer! |
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Mark Rosenbaum Member 
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A tire pressure of 24 psi sounds about right for the bias-ply tires earlier cars might have used, but too low for the radials specified on the JH. Perhaps this is another case where the shop manual was less than perfectly accurate? I suspect that the proper pressure would depend on the type and brand of tires, the rubber used and its condition, whether one wanted a soft or sporty ride, the condition of the suspension, and likely several other factors that escape me at the moment. With the old stiff-sidewall Falken tires my car used to have, I had a somewhat harsh ride with sub-optimum traction at 26 psi. Things felt 'mushy' with pressures much below 24 psi, and those particular tires were so old that they wouldn't hold anything above 28 psi for more than a few days at a time, so I never really experimented with tire pressure. The new Sumitomos I recently installed give the car a smoother ride and much better traction than the Falkens. With these, the steering starts feeling less than perfectly precise below 26 psi, while at 30 psi I get a bit more of a reaction to minor road imperfections than I care for. There's a reasonable balance at 28 psi, so that's where I'm keeping things, for now. I expect this may change as I replace worn suspension bits and learn more about the car's various quirks. |
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Jim Sohl Member
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May I ask, which Sumitomo's ? same f/r ? thanks, Jim |
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Mark Rosenbaum Member
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Jim, Sumitomo 205-60HR13s, same on both ends. My local tire shop suggested I order these online as their distributor doesn't handle that brand, so I bought a set of four from Tire Rack (usual disclaimers). I had the shop remove the old tires, then mount and dynamic-balance the new ones, paying particular attention to high-spot and heavy-spot on each tire/wheel assembly. They did quite a good job. The car rides and corners much better now, is a lot more stable at speed on the freeway, and an assortment of small noises and odd vibrations seem to have gone away. In short, I'm quite pleased with the Sumitomos. They're not as sticky as competition tires, and tend to be ever so slightly squirrely on wet asphalt, but as I don't use the car on the track, nor take it out of the garage when it's raining, neither is a major concern. |
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