The purchase of multifuel vehicles (MFVs) has been incentivized by policies across the globe. Such vehicles are able to operate on more than one source of energy, so they introduce fuel (or energy) choice as one additional dimension consumers decide about. As fuels differ in terms of carbon emissions, this choice has environmental effects. Using 12 years of monthly Swedish data, here I show that the majority of MFV drivers purchase petrol when it is priced at parity with ethanol. Through policy simulations, I document that fossil fuel taxes have limited success in making drivers switch to alternative fuels and can generate economic distortions. The findings question the cost-effectiveness of programmes to incentivize the purchase of MFVs that ignore the fuel choice dimension and highlight the importance of accounting for fuel choice in the analysis of public policy and emerging technologies.

全球政策都鼓励购买多燃料汽车（MFV）。这样的车辆能够使用不止一种能源，因此随着消费者决定增加尺寸，它们引入了燃料（或能量）选择。由于燃料的碳排放量不同，因此这种选择会对环境产生影响。使用瑞典12年的月度数据，我在这里表明，大多数MFV驾驶员购买的汽油价格与乙醇同等。通过政策模拟，我记录了化石燃料税在使驾驶员改用替代燃料方面取得的成功有限，并且会产生经济扭曲。