Minifinity The Classic Mini Forum and Resource | • View topic - 5" vs 6" wide wheels

5" vs 6" wide wheels

tuning, repairs, servicing & maintenance

Moderators: Club Admins, Minifinity Staff

5" vs 6" wide wheels

Postby Daveywantsaparty » Tue 11th Sep 2018, 03:31pm

Hi all,

Is there a significant performance difference between 5" & 6" wide wheels. They are the same 165x 55 R12 tyres. I'm just thinking out loud and a while away from putting the plan into action but I quite like the look of the old minis sans wheel arches. I also quite like tuning engines up too run more horses but do not want to impact performance too much.
User avatar
Daveywantsaparty
 
Posts: 893
Joined: Thu 21st Sep 2006, 11:26am
Location: South West
Drives: Ford Fiesta titanium MP140

Re: 5" vs 6" wide wheels

Postby asahartz » Wed 12th Sep 2018, 10:23am

I'm not quit sure what you're trying to achieve here. It's the tyres that are going to have the most effect on performance. Since they're staying the same, there's not going to be much difference. There may be a slight difference in handling - a 6" wheel will allow the tyre to sit "squarer" if you get what I mean, so there will be less sideways movement. But in terms of the need for wheelarches, no difference.

A standard 12" steelie is 4.5" wide, and that would be fitted with a 145/70 x 12 tyre. But even that required a wheelarch extension. The reason these were fitted (from 1984) was to clear the disc brakes at the front, and in order to match the width of these, the rear drums got built-in spacers and long studs. It's because of these that the arch extensions are needed.

At the end of the day, the only way to (legally) go without arch extensions is to fit 10" wheels with non-spacered rear drums and Cooper S discs at the front. Which is a lot of work and expense just for a particular "look"!

To help compare wheel & tyre sizes, I've installed a wheel size calculator widget on my website.
User avatar
asahartz
Contributor
Contributor
 
Posts: 2355
Joined: Sun 8th Jul 2007, 07:31pm
Location: Mansfield, Notts
Tag Line: Slow down for bends? Why?
Drives: 89 Mini Sky, 71 Mini Clubman, 04 Audi TT V6

Re: 5" vs 6" wide wheels

Postby Daveywantsaparty » Wed 12th Sep 2018, 10:57am

Learnt 2 bits of information there. Didn't realise the standard 12" couldn't fit under without wheel arches and that the standard wheels are 145/60/R12s.

So my question I suppose is related to the performance difference between 145 and 165 tyres. If I wanted to keep the standard look would it impact the performance significantly? I'm aware it's a pressure/area calculation and wider tyres do not always increase grip but would I be losing out leaving the narrower tyres on?
User avatar
Daveywantsaparty
 
Posts: 893
Joined: Thu 21st Sep 2006, 11:26am
Location: South West
Drives: Ford Fiesta titanium MP140

Re: 5" vs 6" wide wheels

Postby asahartz » Wed 12th Sep 2018, 07:49pm

It's quite a while since I drove on standard 12" steel wheels! (though I've got standard 10s on a couple of cars, but they have a completely different feel if you ask me).

I don't think grip is significantly different. I think it's handling that changes. The narrower tyre allows a bit more sidewall movement so there's a bit of difference in the cornering if you push it hard. But it's not a massive difference. Conversely of course, narrower tyres are better in snow - if you're going to drive your Mini in the snow of course! They are good at it but I've tended to protect mine from the weather since I got a TT Quattro :)

The only pics I can find of the two different sizes on the same car are these pair, but they don't quite show what they need.

Image

Image
User avatar
asahartz
Contributor
Contributor
 
Posts: 2355
Joined: Sun 8th Jul 2007, 07:31pm
Location: Mansfield, Notts
Tag Line: Slow down for bends? Why?
Drives: 89 Mini Sky, 71 Mini Clubman, 04 Audi TT V6

Re: 5" vs 6" wide wheels

Postby Daveywantsaparty » Thu 13th Sep 2018, 10:50am

Thanks for the info. I'll keep it in mind once I have some money to spend on the would like to do section and not on the must do section.
User avatar
Daveywantsaparty
 
Posts: 893
Joined: Thu 21st Sep 2006, 11:26am
Location: South West
Drives: Ford Fiesta titanium MP140


Return to Mechanical

Who is online

Users browsing this forum: No registered users and 40 guests