Stock tyre sizes

[ridgey_didge]

The time has come to put new tyres on my stock sedan.  Those currently on the car are getting a bit long in the tooth and I don't want to do a long road trip to the Nats and risk a tyre failure.

The question is, what size is "correct".  At present I have 185/75 x 13 tyres on.  I am told that 185/80 x 13 is closer to the profile of the original tyres. I am able get some in that size.  I can also get 185/70 x 13 tyres.  What does the voice of the forum say is the better way to go?

And for all those who have been unable to sleep at night worrying because my wheels are black (because Grandad liked them to be black because a car with black wheels never looked like it needed washing!) and not the correct colour, I will take this opportunity to get the rims repainted in glorious Cuban Beige.

Cheers
David

[snuff69]

I have 185 80 13 on my cars. As far as I know that's as close as you can get to the original size of the cross ply's. Height wise that is.  Speedo reads good.  Dave

[Geoff_K]

If you define currently available 6-40-13 crossply's as 100% (assumed 3.89 std Diff),
[My Original Dunlop 6-40-13 (Full Tread, never used) is 101%, and a Bald Original Dunlop is 99%]
then 185/80-13 radials are 98%.
and 185/75-13 radials are 95%.

If you change your Diff to 3.55
then 185/80-13 radials are 108%.
and 185/75-13 radials are 104%.

Cheers Geoff

[Plum57]

Hi.  

I did the research on the forum and found the recommendation for 185/80 X 13 as Geoff has explained

I have purchased Sumitomo tyres which make a big difference to the crossplys I had.



Peter

[ridgey_didge]

Thanks guys.  That reinforces the information I had and tells me that is the way to go.
Cheers
David