What's the deal?

 

What are you going to use these tires for? Autocross/track/lapping/driving school/street use?

You're looking in the wrong size for race rubber for 17" wheels.

205/40-17 (has low load rating-only good for one driver/minimum loading- limited track use or autocross-not for daily street use) very light weight (19 lbs), small outer tire diameter of 23.4" effectively lowers gearing. See Toyo Ra-1 for $166 at edgeracing.com (for track/lapping/limited autocross) Can be used in wet with full tread.

Also Kumho Ecsta V700 from tirerack.com from $138 to 168. see below
21 pounds, outer tire diameter 23.2"

215/40-17 is only street tires
215/45-17 at tirerack shows Pirelli Pzero Corsa $221 each For driving school/track/lapping sessions. Expensive, not for street use.

225/45-17 -May rub the wheel wells- trimming with dremmel possible
At tirerack.com (talk to alex) Kumho Ecsta V700 from $148 to 178 (low stock and special order for shaved and heat cycled). 24 pounds, outer tire diameter 24.7". Good autocross tire (leave unshaved for wet conditions), track, or lapping.

Kumho Victoracer V700 23 pounds, tire diameter 24.6" from $148-178
In stock or special order for shaved and heat cycled. Durable for track/lapping/autocross/driving school. Can be used in wet but not as good as Ecsta V700 unshaved.

Avon Tech R 22 pounds, tire diameter 25" (trimming needed for lowered car)
$177 to 192 low stock at tirerack.com Good for track/lapping/autocross/driving school. Not good for wet conditions, more durable than Hoosiers.

Hoosiers $213 each Light- 20 pounds. Not durable, not for wet use
A3SO4 In stock. Good for autocross and track
A3SO5 In stock. Good for autocross and track
R3SO4 low stock. Good for track/ autocross with multiple drivers

Dunlop SP Super Sport Race $119 Special price
Lapping/driving school. Can be used in wet only if unshaved.
Not as sticky as Kumhos or Hoosiers.

Michelin Pilot sport cup $221-236 (shaved) each Good for track/lapping/driving school
More durable/limited street use OK

Pirelli Pzero Corsa $224 See 205/40-17

Yokohama ADVAN A048 $214 each Good for track/wet lapping/driving school

 

For driving school.
Not sure why a 215 would be the wrong size for a 17" wheel
What makes a 205 or a 225 right and a 215 wrong? 215s fit a lowered Mini where as a 205 is obviously narrower and the 225 most like will not fit a lowered Mini without MAJOR trimming of plastic and metal, too which I have already had to do with my street 215s.

Anyway, I then need to make a choice between a 205 and a 225. Would the width of the tire actually make that much difference? I know weight savings on the 205 is good.

Thanks
By the way, the Perelli 215s have been discontinued.

 

you also need to know some 205s (usually R-compounds) run much wider than some 215s.. I remeber seeing a stack of 205/50/15 V700s next to Azenis 205/50/15(which are huge compared to others) and it was considerably taller.

 

215 is the "wrong" size because given the size of the wheel opening for the MINI, the correct fitting tire in 215 width is 215/45-17 or 215/40-17. But tire companies that make competition rubber do not have many customers that use this size so they do not make tires in that size, most are going to be larger from 225mm width on up or smaller at 205mm.

The 205/40-17 is under the minimum load rating for the MINI's weight so you would be using it only for track (best for autocross since that would be one person) In driving school there would be two people (one instructor). talk to Alex@tirerack.com before committing to this smaller size.

So this leaves 225/45-17 which is perfectly good for track but is rather wide and tall for lowered MINIs. Trimming is likely only the plastic areas under the wheel wells- you say you have trimmed some already for the 215 street tires you have- if so you can trim a little more if needed. Do you have two sets of rims? One for street and one for driving school/track?

What is your suspension and what is the wheel offset of the rim being used for driving school? Again- talk to Alex@tirerack for these fitment issues.

I'd say that 225/45-17 is probably your best choice given the broader selection of tires, wider tread and use for on the track.

 

Pirelli Corsa avaliable in 215/45/17, I have them on my car! Advan A048 also available in 215/45/17 from Japan.

Here's the size chat from Advan Japan

http://msj.advan.com/product/yrcTBra...R_BRND_CD=A048

 

I was told by Tire Rack that this size was discontinued and that they only had 3 in stock.
By the way, how do ya like'm?