Fuel economy savings refers to the overall savings based on fuel economy of a vehicle over time. This article examines the potential savings based on the fuel economy of a vehicle. Below is a table which contains several different vehicles from the same production year (2014). The table shows fuel economy, cost savings, and carbon dioxide emissions based on fuel economy. Notice that the lifetime savings of a highly efficient vehicle can be over $10,000!
|mpg (US)||Example||km/L||L/year||kg CO2 produced||Savings from 24 mpg ($1.20/L)||5 year savings||10 year savings|
|18||Jeep Wrangler||7.58||2234||5,343||Costs an extra $668.40||-$3342||-$6,684|
|24||Toyota Camry V6||10.1||1677||4,011||0||0||0|
|30||Mini Cooper Clubman||12.63||1341||3,207||$403||$2,015||$4,030|
|45||VW Golf TDI||18.95||894||2,403*||$939.60||$4,698||$9,396|
|60||Kia Rio 1.1 CDRi||25.26||671||1,603||$1,208.40||$6,042||$12,084|
|73.5||VW Golf TDI Bluemotion||30.94||547.6||1,309||$1,355.28||$6,776.40||$13,552.80|
*Diesel emits 2.6889kg CO2 per liter
This table provides data on fuel use, CO2 emissions, as well as savings vs. a 24 mpg car over one year, five years, and ten years. It also gives examples of a car that falls into each fuel consumption category. While the first five cars are available in North America, the last two heat engine-powered cars are only available in Europe. They are included in this list as proof that fuel consumption of their respective rates is possible using internal combustion, even if North American markets don't currently support them.
Some people planning on buying a new vehicle may consider the long term savings. However, a large majority are concerned with the exterior, interior, upfront costs, and reliability. Therefore, some people may not want to pay higher upfront costs, in hopes that the vehicle will save them thousands of dollars in the long term. For example, vehicles like the Jeep Wrangler are meant for off-roading but are commonly used simply as drive-around vehicles. The above chart shows that over the lifetime of the vehicle (10-year estimate), buying a Volkswagen Golf TDI instead of a Jeep Wrangler will save an individual over $16,000. In addition, the MSRP of a Jeep Wrangler is around $24,000  whereas the Volkswagen Golf TDI is around $23,000. With these savings, its possible to buy a new car after 10 years!
When buying a new car, it's worth considering what the car will be used for. If an individual doesn't need a truck for certain tasks, or a Wrangler for off-roading—a car with bad fuel economy is probably not worth the investment. If one can survive without a truck, the potential savings are tremendous.
The final car in the table is a Nissan Leaf, which is an electric vehicle. Since it runs on electricity, neither the cost savings nor CO2 savings formulas are accurate. We left in the cost savings as a benchmark, but CO2 production varies, depending on theelectricity source. There is a baseline amount of CO2 emitted during car production, and this is higher than production for standard cars. If the electricity used in the car is from coal, then the combination of higher production CO2 and emissions from coal doesn't improve over a standard car.
In Ontario, the estimated reduction of GHGs emissions is about 12,900 tonnes/year from the 3,800 electric vehicles on the road (reducing gasoline usage up to 5.8 million litres/year). However, this significant reduction is due to the fact the majority of Ontario's electricity comes from hydropower and nuclear power.
As for lifetime cost, while a lot of money gets saved on fuel costs, electricity isn't free, and the battery itself has to be replaced. According to Tesla Motors, their battery has to be replaced every five years, or 100,000 miles, and replacement is $12,000 if paid up front when buying the car—or $30,000 if bought directly from the manufacturer. While Nissan does not list battery replacement prices, their replacement program costs $100 per month, which adds $1,200 per year to the cost of driving the car. At 12¢/kWh, the annual electricity cost of the leaf is around $400. Add this to $100/month for battery replacement, and the yearly total is around $1600. While this about $500 less than the estimated fuel costs per year of a 24 mpg gasoline-powered car, it's actually about $300 more than the cost of running a 37 mpg Ford Focus. However, driving more will shrink that gap.