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Why the planet wins in the race to 40 mpg

<p>More and more cars are breaking this threshold. Why has it become such a sacred goal, and what&#39;s the impact on the environment?</p>

If you've been shopping for a car lately, you've probably seen the signs advertising an EPA fuel economy of 40 miles per gallon (mpg) on the highway. But while automakers reach for ever-higher mpg, a recent test revealed that many aren't quite getting there. released results last month from its test of six cars in the so-called 40 mpg club. Only half of the vehicles passed the 40 mpg highway threshold in at least one of the three testing scenarios, and just one -- Volkswagen Passat TDI -- exceeded 40 mpg in all three, including the city scenario, where driving tends to be less fuel efficient.

So what's with the hype surrounding 40 mpg? And will the race to 40 mpg have much of an impact on the environment?

It turns out the excitement surrounding 40 mpg may have as much to do with the advancements made in auto engineering as its does with marketing, according to Michelle Krebs, a senior analyst with

"Two years ago, there were only a couple cars that achieved it. Now we're seeing more and more. Next time it will be 50 (mpg), then it will be 60. It's just a natural evolution of constantly striving for higher and higher fuel economy," Krebs said. "It also has great marketing cache. It looks great in advertisements, especially when gas prices are on the rise and spiking."

The good news is that road to 40 mpg may also be paved with benefits for the environment in the form of reductions in global warming pollution -- if consumers buy into it.

"These vehicles will only have an environmental impact if they're sold," said Jim Kliesch, research director in the clean vehicles program at the Union of Concerned Scientists (UCS). "What manufacturers need to do is make their green cars popular and their popular cars green. By selling their efficient vehicles in volume are they going to make a difference, as far as the planet is concerned."

Photo of dashboard provided by Nicha via Shutterstock.

The race to 40 mpg

Considering that improvements in fuel economy stagnated for the better part of two decades, the race to 40 mpg materialized in a relatively short period of time.

"A few years ago, there were just a few models that came out that were able to break that 40 mpg barrier," Kliesch said. "Now, if you are an automaker and you don't have a vehicle that achieves this fuel economy, you're not in the game."

Some said the industry would never get there. Until a few years ago, some automakers said that with respect to conventional technologies, the fuel economy potential was pretty much tapped out.

"[They said] with the existing engines and existing transmissions, the fuel economy that was being delivered at the time was about as much as could be done and if we wanted to go higher than that, we'd have to go to an alternative powertrain design, such as hybrids," Kliesch said. "That claim proved to be false."

Instead automakers found many options on the design table that could be used to improve fuel economy, such as more efficient engines, better transmissions with a higher number of speeds, improved aerodynamics and use of lightweight materials.

"The 40 mpg vehicles," Kliesch said, "are the fruits of that labor."

Of course, the fuel efficiency push was related to new fuel efficiency and global warming pollution standards introduced by the Obama administration for 2016. Those standards call for a Corporate Average Fuel Economy of 35.5 mpg, which translates to an EPA window label average of about 27 mpg. 

"Automakers really have to get people to buy into this because the government ordered them to make these cars that are highly efficient," Krebs said. "They have to do what they need to to lure people to buy them. They can be forced to make them but can't force consumers to buy them, so they have to do everything they can to get people to buy them."

So far, consumers have been receptive to the many of the six 40 mpg cars tested by, Krebs said. The results, included below, are not entirely surprising since for most drivers, Kliesch said, the EPA window label value will probably be accurate or slightly higher.

1. Volkswagen Passat TDI: 45.1 mpg   

2. Mazda 3i Grand Touring: 38.8 mpg      

3. Ford Focus SFE: 37.9 mpg

4. Hyundai Veloster: 35.5 mpg   

5. Kia Rio 5: 35.3 mpg       

6. Chevrolet Sonic Turbo: 37 mpg         

The TDI engine of the Volkswagen Passat -- the only model to exceed 40 mpg in each of's three testing scenarios -- is extremely popular, Krebs said.

"In fact, they can't really can't build enough to fulfill demand for them," she said.

The Hyundai Veloster was one the fastest-selling cars in May when the typical Veloster sold in 15 days, compared to the industry average of 52 days. Meanwhile, the Ford Focus SFE is ratcheting up big sales each month, as is the Chevrolet Sonic Turbo.

"I think they sold 7,900 last month -- that's huge," Krebs said.

Beneficial to the planet

The environmental impact from these cars, even on an individual level, can be significant, Kliesch said. He estimated that upgrading from a 2007 Ford Focus, for example, to a 2012 Ford Focus SFE could avoid about 1.5 metric tons of carbon dioxide (CO2) in one year in a scenario where the vehicle is driven 15,000 miles annually.

"You're getting the same car in a more efficient configuration that avoids 1.5 tons of global warming pollution per year, let alone holding onto the car for 10 years," he said. "That really adds up."

To get a sense of how that may add up on a cumulative level, it's worth noting that the 2012 Ford Focus SFE's combined EPA city-highway mpg of 33 mpg is slightly lower than the fleet average window label fuel economy of the proposed 2025 fuel efficiency and global warming pollution standards of 54.5 mpg corporate average fuel economy, which UCS estimates (PDF) will translate to a window label average of about 36 or 37 mpg. (Note: This is a sales-weighted fleet average so some vehicles will achieve below and above the 36-37 mpg range.)

UCS predicts the 2025 rule will cut greenhouse gas emissions in the U.S. by 290 million metric tons in 2030. That's the equivalent of removing more than 40 million modern-day cars and trucks off the road for a year.

It will only be a matter of time before gasoline-powered vehicles get even more efficient, Krebs and Kliesch said.

"I would not be the least bit surprised if five to 10 years down the line, people are talking about 50 mpg," Kliesch said.

Krebs is even more bullish.

"I think we're just at the beginning," she said. "Last year was the year of the small car. We saw the Focus, the Sonic, a whole bunch of small cars. This year, I'm calling it the year of the mid-sized car."

Expect to see massive mileage improvements in the mid-sized segment, she predicted, before moving up.

"We're going to see bigger cars get better and better fuel economy," she said. "We started with small cars because it's easier to do, and up we'll go through the whole line."

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