When shopping for wheels I cross-check any potential set with a spreadsheet that I made so I can filter down to specific sizes and weights. I found the list of wheels online, but I cannot find the original website that listed all of the data to give credit to, otherwise, I would list it here. I thought I had it bookmarked but it I guess I didn’t.
At any rate, the original list is very long, with over 4,000 aftermarket wheels. With everything from 6-inch diameter wheels to 24-inch wheels. I was curious what this info would look like in visual form so I uploaded the data to rawgraphs and created the graphics below.
Alluvial Diagrams
Just to explain the alluvial diagrams a bit, the first column is the wheels sizes; the middle column is the wheel weights (lbs); and the last column is the construction method.
I only included wheels from 16-inch to the 18-inch range. It is pretty busy as is and I don’t think I would run anything outside of that range. These are only aftermarket wheels, I may create a graphic with just OEM Subaru wheels.
To no surprise, the forged wheels tend to drift toward the top of the weight list.
16-Inch Wheels
Here the 16-inch wheels are broken out by themselves. There are quite a few forged 16×7-inch wheels in the 11lbs range. Too bad there aren’t a ton of tire options in the 16-inch tire size. I was considering a 16×8-inch wheel but the tire size I wanted (245/xx/r16) was limited to autocross/competition type tires.
17-Inch Wheels
Next up are the 17s. I remember when people complained about new cars being equipped with these “enormous” 17-inch wheels (I’m old). Now they are about as ubiquitous as a wheel can get. On the GD chassis, I think 17s look great; on GRs they look minuscule. I don’t know how long they will last but 17-inch wheels still have a decent tire selection, albeit not as good as 18-inch wheels. One thing that stands out to me on this chart is how many 17x7s there are and the wide range of weights they have. It might be the most diverse wheel size on this chart. 
18-Inch Wheels
And last but not least are the 18-inch wheels. The 18s seem to be pretty evenly distributed in weights, even though they are the heaviest of the group; with 18×7.5 and 18×8 making up the largest groups. The lightest 18-inch wheel from this dataset is 14lbs and the heaviest is about 40lbs! Forged wheels seem to make up the majority of the wheels 16 lbs and lighter. 
Overall, the graphics can’t nail down a specific wheel for you, but they can show you what to expect when shopping for certain wheels. For example, if you are looking for a sub-20lbs 18-inch wheel, expect the bulk of those wheels to be 18×7.5 or 18×8-inches. And the lighter wheel you want the increased likelihood that it will be forged and thus very expensive.
Spreadsheet (excel) – wheel_weights_16-18
B.黒曜石 