When people talk to me about saving money on gas with the Roadster, its usually a joke. I usually respond that it will take forever to justify the Roadster due to saving money on gas, but future electric cars will be better blah blah. Suppose you compare the Roadster to a $60000 20mpg premium burning sports car. You drive 12000 miles per year. Premium gasoline is currently about $4 per gallon and increasing at 8.5% per year. Electricity is currently 11 cents per kWh and increasing at 4% per year. ( Seattle area numbers. ) The Roadster costs $50000 more than the gas car, and you'll need to buy 2 battery replacements that I am guessing will be $15000 each ( one at ~9 years, one at ~18 years ). For a total of $80000 more than the gas car. ( This actually ignores the almost $13000 in tax savings over the gas car ) If you finance that additional up front money and the first battery replacement at 3.8% you end spending $104000 over 18 years. It takes about 18 years to save $104,000 on gas. In 18 years the Roadster will still have value, but the gasoline car will be so expensive to operate it will have near zero value. You likely will have spent a lot less on maintenance as well.