Gasoline forms the backdrop of daily American life – and the smell of it in particular is just as ubiquitous. It’s a potent scent that, though controversial, is hard to ignore. So when Pia Long, perfumer and the co-founder of the London fragrance company Olfiction was asked by an ad agency to create a scent that would evoke the experience of being in an old gasoline-powered car for Ford’s all-electric Mustang Mach-E GT marketing campaign, she couldn’t turn it down.