Taxation is considered as a very important instrument to protect the environment. Motor vehicle taxes are such good examples if governments use them with this goal. Dividing the vehicles into categories according to their exhaust gas ratio which causes environmental pollution, could be a fair way in the taxation of those vehicles that consume fossil fuel. In spite of all economic difficulties to produce a non-polluting car, States should encourage the car manufacturers not only to use tax instruments in order to balance the flexibility of the price policy but also to support the research and development policy (R&D) in order to regenerate the engines with minimal gas emissions into the nature. At this point it is a fact that new solar-powered, electric and hybrid engines, unlike their prototypes, is now in mass production. Tax instrument will be the most powerful weapon to regulate the mass production of the electric and solar power green engines. The difference in the environmental pollution caused by the fossil fuel vehicles and green engines is huge. For this reasons, governments should use the old and well known weapon called taxes.