Graduated approach ignores the decades that have ALREADY been provided as an exception to the lead fuel rules that apply everywhere else - it's already been graduated.
Start at 10% with a commitment to ratchet it up by 4% per year or something. That's enough to start an immediate reduction without destroying the industry.
If you're making choices about engine overhaul now for an overhaul that will last you 7-8 years of light use, fuel costing 40% more at the end of that overhaul will definitely get your attention.
> it's already been graduated.
Doing nothing for decades when it was impossible; and then doing nothing for a decade or two when transition became possible; and then pushing the industry off the cliff is not graduated.
Graduated approach ignores the decades that have ALREADY been provided as an exception to the lead fuel rules that apply everywhere else - it's already been graduated.