I'm cheap, but willing to pay to play. These wheels are all between $200 and $400 each. There are tons of lightweight choices above that price point, I haven't included them here (because I personally can't fathom spending more than 10% of the cost of the new car, on a replacement set of wheels). These are all below 20 pounds each.

**The base-line:**

OEM SGT Wheels: 18x7" @ 26.7 lbs

OEM Dunlop Tires: 215/45 @ 23 lbs

49.7 pounds per corner

OEM SGT Wheels: 18x7" @ 26.7 lbs

OEM Dunlop Tires: 215/45 @ 23 lbs

49.7 pounds per corner

23 pounds is fairly standard for tires around these sizes. But it is possible to find some a bit lighter, even up to 235 wide (for the 8 or 8.5" wheels). I'll may go with the Hankook Ventus S1 noble2: Long treadlife, great reviews, only 19 pounds in the factory 215 wide, or 22 pounds in 235 wide.

Wheels, in order of price:

Konig Milligram 18x8.5" 18.9 pounds $230 each

Konig Kilogram 18x8.5" 19 pounds $240 each

Enkei RPF1 18x7.5" 17.6 pounds $270 each

OZ Ultraleggara 18x8" 18.4 pounds $329 each

Forgestar F14 18x8.5" 18.5 pounds $350 each

OZ Alleggerita 18x7.5" 16.3 pounds $389 each

With the above info, the lightest weight option is the OZ Alleggerita wheels, with the Hankook 215 tires. 16.3+19 = 35.3 pounds, or a savings of 14.4 pounds per corner, or 57.6 pounds total. Which is huge, but at a serious cost: about $2100.

I'm all ears to other options or input. My personal priorities are 18", 7.5-8.5" wide, below 20 pounds, below $400 (but they'd have to be ridiculously lightweight and gorgeous for me to justify even that). In tires, I require all season and good treadlife. I'm over the swapping wheels out with the seasons, or replacing tires every couple years.