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My guess is that future proof designs will be those optimized to achieve fuel efficiency.
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You are almost certainly right. Just as I am almost certain that it will happen (at thet end of the market) when it becomes a major part of the design philosophy of Ferrari, Lamborghinin and similar marques. There will always be a market for conspicuous consumption and there will always be those who can afford it. The problem is, as ever, getting decision makers to grasp where that market starts, or stops, such that the average Joe is not priced away from his own pursuits in order to affect a few who excite the politics of jealousy brigade. Actually the aviation industry spotted this one years ago, hence the low tax status of aviation fuel.