I just read an article that has inspired me to think once more about rotational inertia. Gordon Murray Frames a New Future for Automaking | Autopia | Wired.com I've mentioned in other threads that I am keen on getting semi-solid forged wheels for my Tesla Roadster. I want lighter and stronger than the standard Tesla Motors forged wheels. I am trying to find a way to get SSR Type-C SSF wheels in a 5/110 bolt pattern. They do not seem to have a 16x6 wheel, but they do have 16x7 and 17x7.5 SSR Wheels $450 16x7.0J +42 offset 12.1 lb (normally 5/114.3) $510 17x7.5J +49 offset 14.9 lb (normally 5/100) A set of these for the Roadster might only be $1,920.00 and would total 54 lbs. That's a savings of 14 lbs versus the $2,900 forged Tesla wheels and a savings of 36 lbs versus the stock cast Tesla wheels. The catch is that SSR Wheels would need to make about 40 of these and do crash tests just to change the bolt pattern from what they're already selling in these sizes. I fully expect that the crash testing will raise the price from the $1,920 for similar models quite a bit. Even if they cost more than the Tesla Motors upgrade, I still think it would be worth it. If anyone else is interested, please say so. It's about time that I called SSR Wheels again to see whether they can quote the cost of altering their existing product with the Tesla Roadster bolt pattern. It would be nice to know that someone else might want lighter wheels without sacrificing strength and performance.