It's time for new tires and wheels, and I'm fairly set to get Team Dynamics Pro Race 1.2s for my R56. I'm on Koni FSDs, so not lowered. I'd like to get the widest tire possible, without rubbing, without spacers.

The questions:

225/40r17? and at what offset and rim width?
235/35r17? Offset? Rim width?
235/35r18? Offset? Etc.
and even...
245/35r18? Offset? Rim width?

My car's for Dragon slaying, not tracking.

Thoughts?

 

I should add that I'd prefer to get a 17x8 rim, but I'm unclear about the offset. Wider tires will help me stick to all these North Georgia / North Carolina curves...

 

I am running a 17x7 +35mm Speedline Turini and I just installed Mach V Springs and I am glad I went with a 215/45R17 over the 235/40R17 I originally had ordered because it wouldn't have fit. My 215's rub a little on big dips in the road, I plan to do a few track days later on once I get sway bars and some other stuff. Overall I am extremely happy with the way my setup looks right now.

 

Not sure why the goal of putting on widest possible tire if you want to drive on public roads with confidence.

When performance and handling are key goals you want wheels and tires that match in size and fit which give you the most grip for your given road conditions (consider dry and wet).

Most times I think of the tire first and see if it suits the purpose then check tire sizes that have tire diameter of 24" or as close to it given stock suspension height and need for no rubbing (you don't want to scrape over dips or under full load of passengers).

So either Extreme Summer tires or Max Performance Summer tires would be the first place to look. Problem with Extreme Summer tires is they can wear faster with daily driving (when not at the Dragon) and they are much better in dry than wet with some exceptions.

Once you choose the tire and tire size then choose the wheel size and offset that will give you the clearance you want and fits. No extra wide tires on narrow rims just to have wider tires. You want a perfect fit if you want best handling and performance.

17x7" wheels are a common choice since different offsets are still good and they offer good wheel selection options. 17x7.5 or 17.8" is possible but you can be adding more weight or cost depending on your budget.

If you care about performance and handling then lighter weight wheels can be a big positive but not the only factor. Lighter wheels can be risky to use over very bad roads and can increase cost depending on how light you want to go. Relatively light with moderately priced wheels are a common choice.

Looking just at the tire sizes you mentioned:
225/40-17 No street tires in this size, only R compound race tires. Fits 8-9.5" wide rims, 23.8" tire diameter.
235/35-17 No street or race tires in this size at Tirerack.com.
235/35-18 fits rims 8-9.5" wide, perfect for 8.5" rim, 24.5" tire diam. is usable with stock suspension but only (Pirelli P Zero System) one tire is made for $303 each.
245/35-18 fits rims 8-9.5" wide, perfect for 8.5" rim, 24.8" tire diam. is usable with stock suspension, OK tire selection, No Extreme Summer tires.

Of the Extreme Summer tires:
Bridgestone Potenza RE-71R gives great dry and good wet traction but isn't as comfortable or quiet for daily driving. 200 treadwear.

215/45-17 ($133 each) fits rims 7-8" wide, perfect for 7" rim, 24.7" tire diam. is usable with stock suspension. 22 lbs.
225/45-17 ($155 each) fits rims 7-8.5" wide, perfect for 7.5" rim, 25" tire diam. is usable with stock suspension. 23 lbs.
245/40-17 ($165 each) fits rims 8-9.5" wide, perfect for 8.5" rim, 24.7" tire diam. is usable with stock suspension. 23 lbs.

215/40-18 ($167 each) fits rims 7-8.5" wide, perfect for 7.5" rim, 24.8" tire diam. is usable with stock suspension, 22 lbs.
225/40-18 ($173 each) fits rims 7.5-9" wide, perfect for 8" rim, 25.1" tire diam. is usable with stock suspension, 23 lbs.
235/40-18 ($196 each) fits rims 8-9.5" wide, perfect for 8.5" rim, 25.4" tire diam. is tall and might be usable with stock suspension depending on offset. 24 lbs.

Of the Max Summer tires:
Michelin Pilot Super Sport is the tire of choice for combined street use, daily driving, better comfort, OK treadlife, and very good handling and performance dry or wet. Hard to beat combo, makes it a common choice.
Treadwear 300.

215/45-17 ($147 each) fits rims 7-8" wide, perfect for 7" rim, 24.7" tire diam. is fine for stock suspension. You can use 8" wide rims and they are fine, just watch the offset. 21 lbs. each
245/40-17 ($163 each) fits rims 8-9.5" wide, perfect for 8.5" rim, 24.7" tire diam. is usable with stock suspension. 23 lbs each.

225/40-18 ($186 each) fits rims 7.5-9" wide, perfect for 8" rim, 25.1" tire diam. is tall but usable with stock suspension since tire is not overly wide.
XL version has stiffer sidewall contruction over the Standard Load (SL) version. 22 lbs.

245/35-18 ($203 each) fits rims 8-9.5" wide, perfect for 8.5" rim, 24.8" tire diam. is usable with stock suspension but it will be wide so offset cannot be too aggressive. 23 lbs.

 

Thanks for the very detailed reply.

I'm running Michelin Pilots (at 205/45r17) on R98s right now so I'm very comfortable with them under all kinds of conditions.

Looks like 245/40r17 or 245/35r18 might do the trick.

What offset do you think would be safe? 45? 40? 38?
It also looks like I'll need to choose between a 8 or 9 inch rim ... any thoughts there?

I understand the Team Dynamics will fit a range of BBKs so I'm not too concerned there. (Still making that choice...)

 

If you run a 245 it WILL rub on one side or the other. You aren't going to gain much on the street with that wide of a tire, on the track you might see a tiny advantage. I would stay with 225 or less for optimal performance. With my car being lowered 1.25" and the Cooper RS3-S's I can rail a turn about as fast as possible with no slipping. A good quality 280 treadwear in a 215 will be better than a sub par 235 or 245. I would almost run a 215 R Compound over a 235 street for about the same $$.

 

I run 235 Dunlops on 17X7.5 wheels with Swift springs with a (very) little rubbing when loaded down with big bumps, No damage ever found on car, a little scuffing on tires . Installing different suspension and will be eliminating the rubs, hopefully


https://www.northamericanmotoring.co...nt-photos.html

 

You must have a +45 offset, my 215's scuff a bit on 17x7 +35. I had originally ordered 235's, but they were backordered. Man am I glad I didn't go with those because it would have been rub city.

 

I gotta get Lower Control Arms, right now I am running -2.6 rear camber and it looks retarded.

 

heres my wheel's sticker +40

 

I just can't believe those don't rub, I am super surprised my 215's rub. I figured 215's would never rub even if I went with a +25 or +30 offset.

 

 

When choosing wheels, increased width increases weight and sometimes cost-
17x7" light wheels and under 14 lbs each
17x7.5" light wheels about 15-16 lbs each
17x8" wheels from 19 lbs each

Team Dynamics Pro Race 1.2 in 17x8" et 48 are 19.9 lbs each.

Wheel weight alone is not that big a deal for street use, wide wheels usually means wider tires which can add another 2 lbs.

As for offsets, using 17x8" (compared to OEM 17x7" et 48):

For et 38, the new wheel will be 2.7mm closer to the inner suspension strut and poke out 22.7mm more than before

For et 40, the new wheel will be 4.7mm closer inward and poke out 20.7 mm more.

For et 48, the new wheel will be 12.7mm closer inward and poke out 12.7mm more. Note that Team Dynamics Pro Race 1.2 does not come in offset of 45.
see
http://www.teamdynamicsracing.com/pr...Pro-race12.htm

You don't want your wheel to be 12.7mm closer inward, there would not be enough clearance for the tire and you can risk rubbing on the rear control arm or other suspension parts.

et 38 is OK except for the poke of almost 23mm which is 1". You can make up for this if you run very severe front and/or rear negative camber using adjustable front camber plates and rear adjustable control arms but too much negative camber is going to wear inner tire treads fast and isn't really good except for higher speed and tight turning.

So et 40 seems to be the least risky when using 17x8" wheels. You can get just as good handling and performance using 17x7 or 17x7.5 wheels and the correct tire size if you realize that the "exact tire" not the wheel width or tire size is the most important element to providing sufficient grip and traction when you need it. Bad tires in wide sizes are simply bad. Great tires in almost any OEM MINI size will work fine on public roads.

That's why I say select the tire first then see what sizes are possible. If you are looking at Michelin Pilot Super Sport then yes you can use wider tires but I am not sure that you will get any added benefit with the wider sizes other than the appearance benefit at the downside of added cost.

When racing and on the track a MINI with 17x7" wheels and 205/45-17 tires will do fine.

The other thing to realize is that whenever you use tires that are taller than OEM tire diameter you are increasing ride height and your center of gravity, it's not much but it's the opposite from lowering your suspension.

A race suspension is usually stiffer rated than Koni FSD or OEM so the risk of body lean and movement with hard braking or turning is much less, so rubbing risk is less. If suspension is soft or OEM there can be much more risk of rubbing due to weight shift and transfer depending on the load in the car and the way it is being driven along with the road design and conditions.

17x9" rims with wider than OEM tires would easily rub, for those that go that route, do a search for what fitment and camber they use. Some have narrow stretch fit tires and are looking for that appearance, some have wide arch fender kits.