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Discussion Starter · #1 ·
Hi all,

I have an r53 with stock suspension and 18x8 wheels fitted with 215/35r18 tires. Looking to get new tires and I'm wondering if I can bump them up to 215/40r18 to improve ride quality without them rubbing?

Thanks
 

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2008 Mini Cooper S hatchback,Automatic,Mello Yellow
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All depends on the offset of the wheels being used. But in practical sense just get the thin thin not thin thin thin....shims for them and the longer threaded studs they actually sell for it. Look just like the regular ones. Way easy to find the longer studs for the mini cooper than most cars. And it does not require a huge amount of work and hardware like a full blown shim kit that requires your studs to mate the thick plate type shim. And really long studs to mount the tires.
don't forget to get a set of wheel turning radius stop block rubbers to mount on the lower subframe or shock mount. Cant remember where exactly.
Very close and easy for a set of 215. And relatively affordable.
 

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Discussion Starter · #3 ·
All depends on the offset of the wheels being used. But in practical sense just get the thin thin not thin thin thin....shims for them and the longer threaded studs they actually sell for it. Look just like the regular ones. Way easy to find the longer studs for the mini cooper than most cars. And it does not require a huge amount of work and hardware like a full blown shim kit that requires your studs to mate the thick plate type shim. And really long studs to mount the tires.
don't forget to get a set of wheel stop block rubbers to mount on the lower subframe or shock mount. Cant remember where exactly.
Very close and easy for a set of 215. And relatively affordable.
Thanks for the comment. I'm not very familiar with all this wheel shim stuff. I do know my wheels have an offset of 40mm and I think I noticed there are already some thin shims in the from when I last took the front wheels off to change out the strut mounts. I bought the car used with the current wheels just a bit ago.
 

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you probably can without doing anything else, the factory 18's for example wear 205/40r18 anyway, the rolling circumference being similar to an otherwise stock 205/45r17, then consider that the 17's on stock et48 rims will take both 215/45r17 and even 225/45r17 without fouling anywhere on a standard car so no work is essential there, they will sit close to the inner arch liner at the back but still miss.

205/40 = 82mm wall vs 215/40 = 86mm wall, not going to be an issue in that regard and will actually slightly improve the factory speedo over read.

As far as 205 vs 215, you also should consider all tyres are different overall widths and carcass profiles anyway, so you might be quite surprised just how wide (or narrow) different makes can be. Semi slicks are a great example, significantly wider carcasses at the tread, if it helps, the above sizes quoted are known to fit in such tyre versions, so I really doubt you'll have any issue at all, depends if you wheel offset affects things more, or vehicle height if it's been altered ;O)
 

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Discussion Starter · #5 ·
you probably can without doing anything else, the factory 18's for example wear 205/40r18 anyway, the rolling circumference being similar to an otherwise stock 205/45r17, then consider that the 17's on stock et48 rims will take both 215/45r17 and even 225/45r17 without fouling anywhere on a standard car so no work is essential there, they will sit close to the inner arch liner at the back but still miss.

205/40 = 82mm wall vs 215/40 = 86mm wall, not going to be an issue in that regard and will actually slightly improve the factory speedo over read.

As far as 205 vs 215, you also should consider all tyres are different overall widths and carcass profiles anyway, so you might be quite surprised just how wide (or narrow) different makes can be. Semi slicks are a great example, significantly wider carcasses at the tread, if it helps, the above sizes quoted are known to fit in such tyre versions, so I really doubt you'll have any issue at all, depends if you wheel offset affects things more, or vehicle height if it's been altered ;O)
Thanks for such a detailed response! That sounds very promising.

A couple things though. First, aren't the factory 18's only 7" wide? Would the fact that mine are 8" wide make any difference our is the actual tire size the only thing that matters? Also, you mentioned offset possibly messing with the clearance. My wheels have a 40mm offset and I think they have small spacers with them too. Would this affect it at all?

Sorry I still have a lot to learn about wheel fitment.
 

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yes most OEM are 7j and also et48 in the main so you're right to consider this, the way I see it, your offset difference being just below 50% of the additional 'J' (width in inches) will mean the rim is slightly further inward compared to stock, offset being the distance between the midway point of the rim bead faces vs the mounting face of of the rim, lower = outward, higher = inward, so if an inch in millimetres is 25.4 and your offset being 40 has moved the 'J' midway point 8mm further out, the rim is still 12.7mm wider resulting in it being actually 4.7mm further in at the rim yes? I guess hence why a small spacer has been added, 5mm perhaps but possibly not actually necessary? Although fyi these are better in a hubcentric style which helps locate the wheel centre bore against the hub flange, iirc these might only be available in 6mm, personally I'd use those if any but you may not have scope. Ultimately if you have these size spacers all the above would apply in regard to the clearance to the inner arches and front struts etc, but not necessarily to the outside which of course is further out.

Unfortunately whilst it might read that I'm familiar with a variety of rim sizes on these I'm actually not, I prefer to use OEM wheels myself although I do currently have 16mm spacers under the fronts and 11mm under the rears. I do have aftermarket lighter options in a lower offset (37), just 7J still so they don't pose a problem to me particularly, well they do a little as I'd prefer et42 to cater for my 225/45r17 tyre options, not a fan of 'poke'.

Anyway, I hope the above makes some sense, no doubt someone will be along that has indeed run all sorts. Maybe be mindful of when people have run them and they say they're ok, try to get pictures of their fitment and also try to see what they did to their geometry, as some owners cut trims away, experience other fouling, have tyre or rim poke which they think looks great, and quite often can set fairly extreme negative camber in an effort just to get the wheels they want to fit. Not something I'm a fan of at all and would never recommend fwiw.

Still, your planned tyre size is only +10mm width, and on a wider rim already in play plus the above regarding different brand tyre widths and when only talking about a relatively roomy 205 when on a stock rim anyway, to then a 215 being mounted on this inch wider rim, the real difference at the tyre might not be that much at all perhaps? Hope it works out ;O)
 

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This should get you into the ball park. I was under the impression you wanted more of a concealed look to go with the wider wheels.
 
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