I just got new 16X7 Minilites (beautiful!) from MyMini to replace my 17" S-lites and need opinions on tire sizes & brands to mount. I was originally thinking of 205/50/16's with something like Goodyear F1 GS D3 or BFG KDW 2's. I was later advised that 215/50/16's might be a better choice and have a greater contact patch. There don't seem to be as many choices in that size, but Avon Tech M500 looks pretty good. I do think 50's will work best for me in western PA since potholes are a real threat and I don't want to trash the wheels. Also a track day or autocross may occur on occasion. So maybe you can help me with your thoughts on size, models, and the contact patch variable. Thanks!

 

10mm of contact patch (if that) is not going to net you that great of a difference.

it's the compound that counts. go with the 205/50/16 GS-D3's. those
are actually a lot wider than just 205mm...plus u don't want it too wide
where it starts affecting tramlining. and also, your wheel's only 7" wide...
it might start feeling mush on the corners.

 

I agree! The larger tire is also larger in circumference and heavier. A 7" rim is not optimal for a tire width much beyond 205mm.

 

Below are the specs for the tires in question, taken directly from TireRack. I tried my best to make this easy to read. I highlighted the most important parts.

Keep in mind that using a wider rim when measuring will alter the contact patch width and (to a much smaller extent) the overall diameter as measured at the center of the tread. In this case, the Goodyears may measure out an additional 0.1-0.2" width CP on your 7"-wide rims vs. the 6.5"er's that were used for the official measurement. Even so, the 215's still seem to give you about 10mm of extra width. BUT - they also will be about 1/2 inch taller in diameter when mounted on a 7" wide rim, which effectively raises your gear ratio a bit. I would also predict that the sidewall of the 215 will appear taller (higher profile) on the same wheel when viewing your car directly from the side, which may not be a desirable visual effect.

However, Kenchan is VERY correct that compound and carcass construction are far MORE important with modern tires then these specs. This is where the Goodyears have performed so well for me on 2 previous cars, especially in the rain.


Size . . Treadwear/Ratings . Weight . RimSizes . Measured RimSize . CrossSection . ContactPatch . Diameter
Avon
215/50-16 . . . 280AAA . . 23 lbs . . . 6.0-7.5" . . . 7.0" . . . . . . . 8.8" . . . . . . . 7.7" . . . . . . . 24.5"

Goodyear
205/50-16 . . . 280AAA . . 22 lbs . . . 5.5-7.5" . . . 6.5" . . . . . . . 8.4" . . . . . . . 7.1" . . . . . . . 24.1"
.

 

Go with the options you get with the 205/50/16. I went with that and got the Goodyears you mentioned - they look a lot thicker than stock, they perform astronomically better, and they fit the stock x-lite rim perfectly.

I think I'm about to buy a 7in wide rim, and even with that, I would stay with the 205s because of the choices and how much like like the F1s.

mb

 

In order to maintain near stock diameter with the 215mm wide tire you should consider going to a 215/45-16 tire which will produce a 23.6" diameter. This will also lower the whole car .25" improving the cars CG. The reduced overall diameter will effectively lower the cars overall gear ratio allowing quicker acceleration.

Coopernicus said; "Keep in mind that using a wider rim when measuring will alter the contact patch width and overall diameter. In this case, your 7"-wide rim may give you an additional 0.1-0.2" width CP when the Goodyears are measured. Even so, the 215's still seem to give you about 10mm of extra width. BUT - they also will be about 1/2 inch taller in diameter when mounted on a 7" wide rim, which effectively raises your gear ratio a bit. I would also predict that the sidewall of the 215 will appear quite a bit taller (higher profile) on the same wheel when viewing your car directly from the side, which may not be a desirable visual effect."

There is a little confusion here. The width of the rim does not effect the rolling diameter of the tire, that is controlled during manufacture and the plys of fiber belting around the tire carcass. As stated, the width can be marginally effected.

The sidewall will be taller because the sidewall height is expressed as a ratio between the tread width and the sidewall height. In this case 50% as in 215/50-16. The profile would still be the same between a 205/50-16 and a 215/50-16 as they are both 50 series tires but the 215 tire would have a taller sidewall; 50% x 215 = 107.5mm sidewall vs. 50% x 205 = 102.5mm sidewall. A 215/45-16 would have a 96.75mm sidewall. The stock 195/55-16 tire has a 107.25mm sidewall and an overall diameter of 24.4" just for a reletive comparison. The MC uses a 175/65-15 whos sidewall is 113.75mm with an overall diameter of 23.9".

I hope that this is of some help.

 

I've edited my original statement, but the width of a rim CAN affect the diameter of a tire to a minor extent.

A skinny rim will cause the tire to be more pinched across the width of the bead, more compressed outward towards the tread surface, making a more rounded arch shape across the cross-section of the tread (more of a 'peak' in the very center of the tread).

A wider rim will allow the tire to have a squarer shoulder, with less roundness across the tread, giving the tire a LARGER contact patch and a SHORTER diameter (again, I said by a SMALL amount, depending on the comparative widths of the skinny and fat rims).

Tires with extremely stiff, short sidewall and belt packages (like a Hoosier autocross tire) will deflect in this way alot less then a comparatively soft street tire, but the principal is the same.

 

Roll out on some fatties!

These will fit and are close to the stock size! Tire rack carries a couple tires in this size...

I found this one picture of someone running named "Blakc" running a tire in this size...

RM2k5

 

I just made a similar change to some original Mini 5 spoke 16's from S-Lead 17's and from 205/45/17 runflats to 205/50/16 normal tires. I got the Goodrich g-Force sport. This is my winter setup. I just drove 4 miles from the tire store and noticed that the ride is so much better and the Mini accelerates and turns quicker even with the small weight savings and only slightly less diameter. I can't wait to test this setup further on the way home. I plan to get the same sizes in a lighter wheel and go with the BFG KDWs for my summer and track day setup. I spoke with a guy who has ridden the KDW's and he highly recommends them. He is an experienced track driver and I was able to check out his driving on a club run so trust the recommendation. I am staying away from anything less than 50's for the street has I don't like whammying down on potholes. One of the tires I took off was damaged from doing that. At least it was worn out so I didn't lose out. I don't see the need to go wider for the street, especially if it means going lower profile or larger diameter.

 

Full agree. If you intend to AX you want the extra rubber. I went from 205/55 to 225/50 on 7" rims on my 911 track car which resulted in brake points being moved back up to 100'. Hell, later this year when I zip off the fenders and go to an RSR style I'll be running 275F/315R on 10s and 12s . Certainly, you can over tire a car, but 225s, IMO, on a MCS is not there.