Tire [tyre!] pressures

[twas_brillig]

There's been a bit of discussion on a couple of current threads regards tire pressures:

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From the Haynes manual "MG Midget Austin-Healey Sprite, 1958 thru 1980"

Crossply tyres:
Normal car load: Front 18 psi; rear 20 psi
Maximum car load: Front 18 psi; rear 24 psi
Sustained high speed driving: Front 22 psi; rear 28 psi

Radial tyres:
Normal: Front 22 psi; Rear 24 psi
Maximum: Front 122 psi; Rear 26 psi
Sustained: Front 28 psi; Rear 30 psi

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From 'General Data' in The Austin-Healey Sprite Mark I Workshop Manual, Issue 6, from The British Motor Corporation (no date)advises:

Pressures:
Front 18 lb./sq.in. (1.27 kg.cm2)
Rear 20 lb./sq.in. (1.41 kg.cm2)
For sustained speeds in excess of 80 to 85 m.p.h. (129 to 137 k.p.h.) increase pressures to:
Front 24 lb./sq.in. (1.69 kg.cm2)
Rear 26 lb./sq.in. (1.83 kg.cm2)

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The Haynes manual identifies wheels as
Pressed spoked: 4 1/2 JSL x 13
Pressed disc: 3.5D x 13
Wire: 4J x 13

They also show Tyres
Type: 5.20 x 13X Crossply or 145SR x 13 Radial

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I'll add this info to the other two threads.

Doug

 

[theleisure]

Thanks for posting that Doug. I can add one thing. Pressed disc wheels are 3.5 x 13 but rostyles (at least the set of early rostyles that I had) are wider. I'm pretty sure they were 4.5 x 13. I put period correct disc wheels on my '66 and I didn't considered the fact that there might be a difference in width before I made the switch.