How wide can you go

What is the widest tyre that can be squeezed on to a 6" rim? I know 205s will go on but will 215s?

The nominal recommend difference according to the tyre industry association is that the wheel should not be less than 70pc of the width of the tyre. That said each tyre by size and model from each manufacturer has a minimum and maximum wheel size. This is not seemingly a easy thing to find on a general basis unless you have access to the tyre industry association website which is a pay site. That said an email or phone call to a manufacturer will get you started. Suppliers in my experience are not so helpful.

11/60 wrote: The nominal recommend difference according to the tyre industry association is that the wheel should not be less than 70pc of the width of the tyre.

That is very interesting thanks.
A 6" rim can therefore take a 215 tyre; the rim would be 80% of the tyre width approximately.
You are right about finding the info. I found some info but nothing really useful like your 70% rule.

I only know that from talking to a wheel manufacturer at an open day, he was showing me the book with it all in but wouldn't accidentally let me have his copy of it. Shame that.