By using AutoEcoRating, a car shopping website can compute an “eco-value” that shows consumers how much green performance they’ll get per greenback.
A good part of the green equation is saving fuel, but most consumers are looking for a value proposition that balances what they want in a car against how much they’ll pay for gas and the cost of the vehicle.
Ever since hybrids hit the market, math-savvy car reviewers have crunched the numbers and concluded that it often takes a while for savings at the pump to pay back the up-front costs. On purely pocketbook terms, it’s often an econobox that wins.
But if microeconomics made the world go round, we’d all still be driving slightly evolved Model T’s and they’d all still be black. Most consumers assess what a vehicle is worth to them against a wide range of features as well as styling and performance. For a growing number of car shoppers, a certain environmental feel-good factor is part of the equation. This subset of the market sees greenness as something that goes beyond just the dollar value of the gas savings.
Because AutoEcoRating measures all the components of automotive eco-friendliness, comparing our eRatings to vehicle price is a uniform way to measure eco-value. If you divide a car’s eRating by its price, the result is a green “bang for buck” ratio. Since eRatings fall in a two-to-three digit range while prices are in the thousands, computing this ratio per thousand dollars yields a number in a reasonable range. For example, a $25,000 car with an eRating of 100 has 4.0 as its eco-value ratio.
Using the AutoEcoRating algorithm, such comparisons can be made for vehicles in any segment of the market. To show how it works, let’s take a look at cars that have some of the highest eRatings as well as those with some of the lowest sticker prices. That means a sample of battery electrics, hybrids and economy cars, as shown in the table below. We use Manufacturers Suggested Retail Price (MSRP), including destination charges but excluding incentives, as a basis for comparison.
The "eco-value" ratio: finding best green buy for the dollar
Make and Model Base
MPG eRating eco-value
Chevy Cruze LS $17,595 30 144 8.2
Chevy Cruze Eco $21,215 31 145 6.8
Toyota Prius c One $19,710 50 201 10.2
Toyota Prius Two $24,760 50 195 7.9
Mitsubishi i-MiEV $29,975 112 269 9.0
Nissan Leaf $36,050 99 232 6.4
Nissan Versa S $13,900 33 134 9.6
The best value turns out to be the 50 mpg Toyota Prius c, which has an eco-value of 10.2 based on its eRating of 201 and $19,710 sticker price. The second best is a base model Nissan Versa S, with an eco-value of 9.6 for a version equipped with an automatic transmission (Nissan’s CVT) that carries a $13,900 MSRP. This sample includes only automatics; for manuals, the prices would be lower and the fuel economies would be similar or slightly better, giving even higher eco-values.
Factoring in whatever incentives are available makes a difference, especially for electric vehicles (EVs) that qualify for a hefty tax credit. The price a consumer pays then goes down and so the value goes up. Big incentives, such as the tax credit of up to $7,500 now earned by most EVs, push the eco-value up a lot. Take the Mitsubishi i-MiEV, whose eRating of 269 puts it in first place along the AutoEcoRating scale. Without a tax credit, its $29,975 MSRP results in a third-place 9.0 eco-value. However, if a buyer qualifies for the maximum tax credit, the i-MiEV’s price falls to $22,475 and its eco-value jumps to 12.0, making it the winner (with some help from Uncle Sam).
Bottom line: the Toyota Prius c offers the best eco-value before incentives, but is topped by the Mitsubishi i-MiEV once the electric car tax credit is factored in.