 have the idea that, you know, 87, 89, 91 doesn't necessarily impact them. His car was a well-known import, high-performance version of that import. Open up the fuel door, it specifically says 91 octane. Now, can you put 89 or 87 octane in them? Yes, you can. Most of them have NOx sensors and other computer controls, so when that lower octane gasoline pre-detonates, which can damage the engine badly...