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Tire size substitution

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NutmegCT

NutmegCT

Great Pumpkin
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Probably old news to everyone here, but I found an article in Moss "British Motoring" summer 2004, to be very helpful in figuring out what "modern metric" tire could replace an old "inch" tire from the 1950s and 1960s.

For example, instead of paying for a "classic reproduction" 5.90-15 tire at $170, you could get a BFGoodrich 155/80R15 for $75. The 155/80R15 very closely parallels the measurements of the original 5.90-15.

I think the process of deciding is made very clear in the attached article.

Tom
 
Thanks J-P. Here's another, which also gives visual comparisons.

https://www.tacomaworld.com/tirecalc

I was always stumped by how to compare a "5.90-15" to a modern "xxx/xxRxx" type with the online calculators, as the early numbers don't show the aspect ratio.
 
When I needed tyres on the Jag, I did a lot of researching. I keep a copy of this handy.

Pre-1964 6.40X15

1965-1972 735-15

80-series
metric 185-15

Alpha-numeric
78 series E78-15

P-metric 75
series radial P195/75R15

P-metric 70
series radial P205/70R15



Optional Radials in 1960's: 185HR15 (factory)
As installed: 165R15 86T
 
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