The excise tax on petroleum has been calculated in two steps since 2006.
Source: UNCSD Secretariat (2010) Questionnaire for the Member States on Experiences, Success Factors, Risks and Challenges with Regard to Objective and Themes of UN Conference on Sustainable Development (UNCSD)

The excise tax on petroleum has been calculated in two steps since 2006 : the general excise tax is ISK 9.28 pr. liter, while the special excise tax is ISK 32.95/liter (ISK 34.92 if the petroleum contains lead). Therefore the overall excise tax on petroleum is ISK 42.23 (ISK 44.20 should the petroleum contain lead), while motor vehicles that run on diesel are imposed with a tax of ISK 45 pr. liter. The differentiation in the tax scheme is worth noting, as it clearly characterizes the tax as a regulatory instrument with an environmental focus.