- As for curbing greenhouse gasses, create a yearly tax on whomever a vehicle is registered to, for every cylinder beyond four (the more cylinders beyond four the higher the tax). And start it immediately, with reasonable taxes and then ramping up over time (5 - 10 years) until it hits it maximum tax amount. This gets people used to paying the tax immediately for awareness and to also start training them to look for alternatives to gas guzzlers. This also gives manufacturers time to update their fleets with better options. (Look at the Mustang Ecoboost -- 4 cylinders and it hauls ***). But no Republican would ever vote for this (I'm sure it wouldn't be popular with all Democrats)