Keep in mind how modern cars usually work, including the Scoobies. Knock detection isn't psychic, it doesn't predict knock in advance. It detects knock as it happens THEN pulls back. So you do get some knock before the car adjusts its behavior to compensate. There is a chance that even just that little initial knock can still bone your engine. Can you run lower octane gas? Sure no problem. As long as you understand that it requires the driver to tip-toe on the gas pedal. If you can do that you'll be okay. If you drive on the highway alot and romp on the onramp to merge, or you habitually stomp on the gas to overtake alot then I wouldn't suggest it.