Need some help please

2005 MCS with std suspension

I have at the moment std 17" wheels and 205/45/17 run flats

I want to go 18"wheels so what size tyres do I need
do I need 18x7 or 18x7.5 wheel and what tyre size

Or should I just get 17" wheels and 205/45/17 non run flat tyres

I don't want to have any problems wit 18'' wheels and tyres with tyres rubbing or touching things

Note..on the inside of my door where tyre pressures are it has that 205/40/18 tyres can come with this MCS

Note..205/40/18 run flats are not available (Australia)


Cheers
cw

 

How are your roads?

Are they smooth or full of potholes and bumps?

Are these tires for warm weather or for use in cold or some snow?

Do you care about how much the tires cost or how long they last?

Do you care about responsive handling or do you want appearance more?

Once you have determined these things then we can narrow down your choices.

For 18" wheels you can choose either 18x7" or a wider rim but 18" rims are heavy enough without being wider than OEM. As a wheel gets heavier the handling may be slower to respond, not a big factor if looks are a priority. Most tire sizes will fit rims 7-8" wide or even wider.

All tire sizes for 18" to fit the MINI will need a tire diameter of about 24.0 to 24.7" tall to give enough clearance with stock suspension and under full load on uneven ground.
This means that all sizes will have a fairly stiff 35 or 40 series sidewall that would be jarring on anything but smooth roads.

If you move to nonrunflat tires and choose a size that is 40 series it might feel like OEM 17" runflat tires in firmness.

18" tire sizes to choose from are-
OEM 205/40-18 fits rims 7-8" wide, tire diam. 24.4"
215/35-18 fits rims 7-8.5" wide, tire diam. 23.9"
215/40-18 fits rims 7-8.5" wide, tire diam. 24.7"
225/35-18 fits rims 7.5-9" wide, tire diam. 24.2"
235/35-18 fits rims 8-9.5" wide, tire diam. 24.5"
245/35-18 fits rims 8-9.5" wide, tire diam. 24.7"

You want a tire that doesn't weigh too much and fits the rim you have, usually 205 to 225mm wide tires will work.

Some sample tires-

205/40-18
Michelin Pilot Super Sport (Max summer tire) $171 each, 300 treadwear, excellent handling (dry or wet) and comfortable for street use, not for cold weather or any snow.

On a budget
215/35-18
Sumitomo HTR ZIII (Max Summer tire) $116 each, 300 treadwear.
Good value summer tire on a budget.

With comfort in mind with value-
215/40-18
Continental ExtremeContact DW (Max Summer tire)
$154 each, 340 treadwear

With comfort in mind and longer treadlife, and for use in cold weather and light snow-
Continental ExtremeContact DWS (ultra high perf all season tire)
215/35-18 $142 each, 540 treadwear, 18 lbs
215/40-18 $148 each, 20 lbs

 

what about running 17" with 205/50/17 tyres
how will this go

 

205/50-17 will fit the OEM MINI 17x7" rim but is taller than OEM tire diameter by a little over 0.5".

Usually when replacing tires you want as close to OEM tire diameter so that the speedometer and odometer are accurate and the tire proportions to the car are close to how the car was designed.

A 25" tire diameter as with 225/45-17 and 205/50-17 can be used but you increase ground/road clearance raising center of gravity, and decrease wheel gap thus increasing risk for rubbing under load or with a full load.

If you are considering 205/50-17 for the taller sidewall you would do as well with 215/45-17 which is just a little over OEM tire diameter and gives more clearance than the 205/50-17.

 

So in hind sight the best tyre for a 17x7 wheel is a 215/45/17 tyre

Want to get rid of my 17" s/lights and run flats and don't know what wheel and tyre size to get