A wise old Indian Chief once said, "White man always leaves out the best part." The article by Shell Oil folks that have a significant interest in maintaining the status quo does a lot of that. He says there is no way to keep boosted engines from pinging unless leaded fuel is used. Granted, TEL was used in warbirds of WWII but even that wasn't enough for the turbo-supercharged Wasps, Merlins, and Allisons of the day. Amazing what a little water and methanol would do to solve the problem. For normal levels of boost, I think even low octane, no-lead gas would work with water methanol injection but it would cost more and be more complex, albeit healthier than breathing TEL fumes. Shell guy also neglects to mention adverse health effects of TEL but instead only says banning it is for alleviating concerns about the environment. Do you think that breathing TEL fumes is unhealthy? Interesting to me that T. Midgely. the guy that discovered octane boosting effects of TEL nearly killed himself when he demonstrated how "safe" TEL was, by publicly dunking his arm in a tub of the liquid. Seems he was so sick with lead poisoning that evening that he was unable to make his presentation on the safety of TEL to a scheduled assembly.