Tyre experts?

[Agile]

Whats the difference between my car's 155/70 R13

and an 155/R13 78T ?

Are they interchangeable?

If not then by how much not?

Tony

 

[JonB]

Hi Tony
I dont know but try blackcircles.com
They seem to have a full list .
JonB

 

[SteNova]

if there is no % measure, (the 70 in the first one) then assume they are 80%

the 2nd ones you mention are 31mm/5.67% bigger in diameter

 

[Stivino]

The 70 part means that the profile (depth) of the tyre is 70% of the width, which is 155. So 155 X 70% is the profile.
When a tyre doesn't have the profile written on it, it's assumed to be 80. So, your other tyre is a 155/80/13.
They are pretty much interchangeable but you shouldn't mix the two on the same axle. HTH.

 

[TicklyT]

155 ÷ 70 is the profile.

Close, but no cigar.

155 ÷ 70 would be a rubber band about 6" wide and 3/32" thick.
155 X 0.7 is the tire profile.

[/Pedantry]

 

[Agile]

Or probably 155 x 70% if we wanted to be totally accurate.

Thanks for this info its not something you think about very often but it helps to know a little more about what it means.

Tony

 

[Stivino]

Oh well I messed up with the symbols. I knew what I was trying to say, I just messed up the way I said it.
Thanks for setting the recoed straight.

 

[crank39]

No their not, a 155/70x13 tyre has a shorter sidewall that a 155x13.

A 155 x 13 is actually a 155/80x13 but because 80 is the standard sidewall height the 80 is never used in markings, some other info....

155 is the tyre width in mm

70 is the sidewall height expressed as a % of the tyre width, ie it should be 70% of 155mm

13 is the rim diameter as in inches

R just means its a radial tyre

78 is the load rating

T is the speed rating

This is all from memory from when i was in the trade over 20 yrs ago but heres a helpful key....

http://www.autow.co.uk/smmt/images/tyre.gif

 

[Agile]

That 78 load rating would explain why that tyre is listed as a van tyre!

But whats the load rating of the 155/70 13R ?

I think several of us are learning from this!

Tony

 

[empip]

http://www.tyres-online.co.uk/tech.asp

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