OK, I now have my Winter rims and tires installed. Here are the pics and couple of others of my license plate (Didn't want to pay for a full personal plate)

Those actually look pretty good. I was afraid the size difference would be too much but that's not too bad at all. If I could find a good tire to 2nd gear speed ratio on something that fits one of these smaller lighter tires they might be good for SCCA SOLO SM2.

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255/50R16 Hoosier A6 25.8" OD
275/45R16 Hoosier A6 25.3" OD
or
265/45R16 Kumho V710 25.2" OD

Wow so much sidewall, looks like a 4x4. I'd post pics of my winter rims... but they're sitting in the garage

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1993 talon tsi awd - stock on the outside, modded on the inside
2007 solstice gxp - Solo Performance 3" mach exhaust + hiflow cat - dyno sheet

why winter rims..small tires do bad in cold?

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THE SKYSTICE

A big Thank you to my Friends, Family, God, Solsticeforum.com, Autoloc, Meguiar's, Dunlop, Installer Institute, and Team Jinsoku!!

From Tire Rack's Winter Tire Tech Section:

Priorities for Sizing Winter Tires Are Different

Does your sports car, coupe, or sedan use wide, low profile tires that are mounted on large diameter wheels? Or does your light truck use large flotation-sized tires? If you're going to drive through lots of snow this year you'll want your winter tires and wheels in sizes that help put the laws of physics on your side.

A wide, low profile or large tire has to "plow" a wide path through snow which causes more resistance. The narrower the tire, the easier you can get through snow. We'll help verify sufficient load capacity and the appropriate diameter for your vehicle when you speak with one of our sales specialists or use Winter Shop by Vehicle.

Winter tire sizes should be based on one of the following:

The Optional Tire and Wheel Size from Your Vehicle's Base Model

This is often the easiest way to select an appropriate narrow tire for your car or truck. For example, a 2003 Lexus IS300 would store its original 215/45R17 tires in favor of optional 205/55R16 tires on 16" wheels.

A Minus Size Tire and Wheel

Minus Sizing is simply traditional Plus Sizing techniques used backwards. For example, a 2003 Volkswagen Jetta GLX VR6 would store its original 205/55R16 (or optional 225/45HR17) tires in favor of Minus One or Minus Two size 195/65R15 tires on 15" wheels.

In both of these examples, not only would snow traction be enhanced, but the cost of a Base Model or Minus Size winter tire & wheel package is usually lower than a package maintaining your vehicle's original size tires and wheels.

Speeds are based off the GXP's 57mph limit in 2nd gear. With the Kumho and the 16" light weight wheels you're talking $300 per corner for a total of $1200 compared to getting light weight 18" with the Kumho for $600 per corner for a total of $2400.

16" tires.

• 255/50R16 Hoosier A6 25.8" OD
  • $214
  • 25 lbs
  • 2nd gear - 2.4% too fast [55.6 mph]
• 275/45R16 Hoosier A6 25.3" OD
  • $225
  • 24 lbs
  • 2nd gear - 3.5% too fast [55 mph]
• 265/45R16 Kumho V710 25.2" OD
  • $185
  • 24 lbs
  • 2nd gear - 4.8% too fast [54 mph]

Their 18" counterparts.

• 245/40R18 Hoosier A6 25.3" OD
  • $261
  • 21 lbs
  • 2nd gear - 3.6% to fast [55 mph]
• 245/35R18 Kumho V710 24.8" OD
  • $240
  • 23 lbs
  • 2nd gear - 7.2% too fast [53 mph]
• 245/45R18 Goodyear Eagle F1 GS-2 26.6" OD (GXP Stock)
  • $242
  • 27 lbs
  • 2nd gear - 57 mph

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Also...
The Sport Edition D3 16" wheels weigh 18.4lbs just like their SSR and OZ 18" counterparts. This would give them a slight rotational inertia advantage over the 18" wheels.

The tool I was using to calculate tire info doesn't cover tread contact patch or width. How does this being a 7" wide wheel impact the 265/45R16 Kumho V710 for example? It's already wider then a stock 245/45 but it's being pinched onto a rim 1" less in width?

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The general rule is that you lose/gain .2" for every .5" difference in rim width.

Example:

We measured the section width on the 265/45R16 Kumho V710 as 11.2" on a 10" wide rim. Mount that same tire on a 16x7" Sport Edition D3 and the section width would then be 10", (1.2" loss due to the 3" difference in rim width).

Ok, so a 265/45R16 (10" as you mentioned) on a 7" rim would then still be wider then the 245/35R18 V710 (9.8") being used by some Solstice racers.

I see your site lists the 265/45R16 as being for 8.5-10" wide rims though. What are the issues/risks of putting them on a rim 1.5" smaller then the recommended size? I know some of the Hoosier drivers are putting the 285 (10.5-11.5") & 295 (9.5-11") tires on 8" rims too though.

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I would be one of those Hoosier guys putting 285/30R18 A6's on 8" wide wheels . Downsizing 2.5" from the recommended size is Ok on the really wide Hoosiers due to how flimsy the tread area is. They have very stiff sidewalls but the tread base is very soft. The Kumhos are a bit stiffer in the tread base which is why the general concensus is that the 285/30R18 Kumhos won't mount up correctly even though thier recommended rim width range is 9.5"-10.5". BTW- I'm pretty sure that no one has tested this theory and personally I think they might work fine on the 8" wide wheel, (FM please correct me if you've tested this).

On the 265/45R16 you have WAY more sidewall than guys like me running the 18's. For this reason I see no problems putting that tire on a 7" wide wheel. Like I said you'll have right around 10" section width and it shouldn't look too pinched down. If you were using these on a road course you might have a problem due to the tire crowning on long straights causing irregular wear in the center of the tire. For autocross you shouldn't run into any problem due to how short the runs are.

Well, today was finally the first major snow here. It was actually more like freezing rain.

My wife had the car, and reported back that the car handled fine with the winter rims and tires.

Pictures are in the first post of this thread. Not looking so clean now