Increasing fuel economy is a simple way to make cars cleaner and better for the climate

The electric vehicle revolution is charging ahead: Global passenger EV sales grew by 103 percent in 2021. In the last quarter of 2021, they accounted for 13 percent of all new vehicle sales.

And many more EVs are continuing to roll out. Just last week, Ford delivered the first electric version of its F-150 truck, the best-selling vehicle in the United States, to a customer in rural Michigan. Ford plans to invest $25 billion in EVs through 2025. General Motors has two versions of the Bolt for sale, and is planning to begin delivering its Hummer EV this fall. By 2025, GM will invest $27 billion in EVs and by 2035, the company says it will be all-electric.

As gasoline prices reach record highs and the summer road trip season kicks off, getting around without gas is a more appealing prospect than ever. And this year may be an inflection point, where the number of internal combustion engines on the road reach their peak. Countries like Finland, Germany, and New Zealand have plans to phase out gasoline vehicles entirely.

But while many car companies are driving toward a future filled with electrons, it’s their conventional cars that will be most consequential for the global climate in the meantime. Transportation is the largest source of carbon dioxide emissions in the US — and cars and light trucks account for 60 percent of this share. In 2021, President Joe Biden committed to cutting US emissions 50 to 52 percent below 2005 levels by 2030, which would demand huge cuts in emissions from cars, vans, pickup trucks, and crossover SUVs.

However, despite their growing popularity and availability, electric vehicles still account for just 3 percent of new car sales in the US, and the average car stays on the road for more than 11 years. That means, by 2035, only 13 percent of vehicles in the US may be electric.So even though EV adoption is accelerating, it will take them years to catch up to gasoline and diesel cars.

Meeting climate change goals thus demands a less glamorous and more incremental approach too: Increasing efficiency. And that requires regulations, which the auto industry, oil companies, and some states have long resisted.

“Efficiency regulations are still really important even as automakers are making pledges to electrify their fleets,” said Kate Whitefoot, an associate professor of engineering and public policy at Carnegie Mellon University.

In particular, California has been a leader in setting cutting edge targets for pollution from vehicles, pushing automakers to hit increasingly tough benchmarks. It’s a privilege the Golden State has held for decades due to a legal quirk. But earlier this month, 17 state Republican attorneys general sued to block the Environmental Protection Agency from upholding California’s special status. If successful, the suit could derail progress toward more efficient cars and trucks.

There are other hurdles too. Americans still love big cars. New cars are getting more expensive. The economy is unstable, and inflation and supply chain crunches are making it harder to buy new cars, including EVs. For carmakers, that’s all making it tough to plan ahead. They crave certainty, which is why some are pushing themselves harder to clean up their fleets than regulations require, with EVs and with increasing efficiency.

Why the whole country cares so much about California’s car rules

California historically received an exemption from federal rules on emissions from cars and light-duty trucks under the Clean Air Act. With that privilege, Sacramento has set even more stringent regulations than Washington has for pollutants coming out of tailpipes, including nitrogen oxides, particulates, and, in 2013, carbon dioxide.

A key thing to note is that vehicle emissions and fuel economy are closely related, but they aren’t the same thing. They’re also regulated by different agencies. California can set air pollution standards, but only the federal government — namely, the Department of Transportation’s National Highway Traffic Safety Administration — can set fuel economy rules.

Additionally, since 1990, the Golden State has been rolling out a mandate for zero-emission vehicles that requires manufacturers to sell a certain number of battery-electric vehicles, plug-in hybrids, and hydrogen-powered cars. In so doing, California has become a laboratory for regulations on cars and trucks.

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“California gets to experiment,” said Meredith Hankins, a senior attorney at the Institute for Policy Integrity at the New York University School of Law. “They get to kind of go first and explore how much can we reduce emissions.”

When California implements a set of regulations on cars, the federal government watches and sees how feasible they are and often uses the state’s experience as the basis for new nationwide regulations. But as the most populated state and the largest auto market, California can set the de facto standard for much of the rest of the country even before the federal government can act.

The California Air Resources Board, which regulates pollution from vehicles, is now in the process of updating its regulations for clean cars. The agency’s proposal again aims for a higher pollution standard than the federal government. It also aims to increase the number of zero-emissions cars and trucks sold in the state. “The federal government does not have a requirement for [zero-emissions vehicle] sales, unlike California, so there is nothing to compare,” CARB Spokesperson David Clegern told Vox in an email.

Right now, 17 other states have adopted California’s benchmarks for vehicle pollution outright. Car companies, rather than redesigning their vehicles for every state, usually use the California rules as their benchmark for the whole country.

That special status didn’t sit right with some people, including former President Donald Trump. He revoked California’s authority to set its own emissions standards. Then, President Joe Biden restored the waiver in March.

Republican attorneys general from those 17 other states then sued to stop the EPA from restoring California’s special status, arguing that it gives California unfair leverage over the market and raises the costs of cars. And a group of 20 more states and the District of Columbia came out in favor of keeping the status.

It’s hard to say where the litigation will go, but courts have long upheld California’s special status. “It’s a very well-established provision, and now red states are arguing that it’s unconstitutional,” Hankins said.

This year, the federal government updated its own vehicle efficiency rules, known as Corporate Average Fuel Economy (CAFE) standards. They require the US auto industry to average 49 miles per gallon across the fleet by model year 2026, up from the current benchmark of 28 mpg enacted under Trump. According to the Transportation Department, the new rules will cut fuel consumption by more than 200 billion gallons through 2050 compared to the current standard.

“These improvements will also make our country less vulnerable to global shifts in the price of oil, and protect communities by reducing carbon emissions by 2.5 billion metric tons,” Transportation Secretary Pete Buttigieg said in an April statement.

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For the $100 billion US auto industry reeling from global supply chain disruptions, getting any standard nailed down is a relief. “Uncertainty in and of itself has a lot of impact on the industry in terms of long R&D planning,” Whitefoot said. Designing a car can take years and if the goalposts keep moving, companies struggle to get cars ready for the showroom. Some car companies have challenged federal regulations and California’s waiver in the past but are now on the sidelines, hoping that the dust settles quickly.

Automakers know how to build cleaner, more efficient cars, but will people buy them?

It’s clear that the global auto industry thinks that electric cars and trucks are the future. Toyota, the world’s biggest carmaker, is investing $17.6 billion to produce a line of 30 battery electric vehicles by 2030. Mercedes is planning to introduce 10 new EVs this year. Nissan plans to launch eight EVs by the end of 2023. Acura, Audi, BMW, Honda, Hyundai, Land Rover, Toyota, Volkswagen, and Volvo all have big EV releases scheduled between now and 2025

And, of course, there are car companies that exclusively make EVs, like Lucid, Polestar, and Rivian. EV manufacturer Tesla became the most valuable car company in the world.

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But car companies also have a lot of room for improvement with their gasoline and diesel offerings. Some are already using new technologies to make their fleets do more with less. “Electric hybridization represents the ultimate efficiency approach for gasoline-fueled vehicles,” according to a report last year from the National Academies. “The internal combustion engine can achieve higher efficiency when specifically developed to take advantage of hybrid synergies.”

This includes a range of systems for melding electric motors to gasoline engines, from automatically stopping and starting engines at stoplights, to acceleration assist systems, to plug-in hybrids that can run fully on electricity or gasoline. Meanwhile, the engines themselves can run at higher compression ratios, and automakers can add more gears to transmissions in order to increase fuel efficiency. Using lighter materials like aluminum and improving aerodynamics can also help cars travel further with less fuel.

The problem is that Americans increasingly want more legroom, ground clearance, trunk space, and power, which in turn demands more energy to move around. That has “offset some of the fleetwide benefits that otherwise would have been achieved from the improvements within each vehicle type,” according to the EPA’s automotive trends report. Even electric vehicles are getting bigger, eating into their performance advantages.

Carmakers also like making larger cars because they tend to have higher profit margins. In 2018, Ford said that, aside from the Mustang, it would stop making sedans altogether, instead focusing on trucks, SUVs, and crossovers.

Since fuel economy regulations are scaled by the size of the vehicle, it’s a further incentive to make larger cars. That’s helped create entirely new categories of vehicles like the crossover, a taller, heavier vehicle built on a car platform (in contrast to sport utility vehicles, which are typically built on truck platforms). SUVs and crossovers now account for half of cars sold in the US. Now, Ford’s electric Mustang is an SUV.

Bigger cars are also more expensive. The average new car in the US now costs more than $47,000. The median income in the US is $41,000, and 85 percent of new car purchases require loans. Automotive debt in the US now tops $1.4 trillion. For most households, transportation is the second-largest expense after housing, and for much of the US, there’s no way to get around without driving. People are driving more as well.

On top of all that, big cars are more dangerous for people outside of them. Larger vehicles have contributed to a rise in pedestrian fatalities. These vehicles often have massive blind spots that are particularly dangerous for children. But for passengers and drivers, they’re safer than smaller cars.

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All of this has created a situation where it’s harder to convince people to buy new, more efficient cars or electric vehicles, and those vehicles are not as clean or safe as they could be.

Some lawmakers have called for government discounts to encourage people to swap their gas guzzlers for fuel sippers alongside more incentives for EVs. The Biden administration is also investing the infrastructure to support cleaner vehicles, including $7.5 billion to build 500,000 EV charging stations across the country and close to $10 billion to support hydrogen fuels for vehicles.

But the cars themselves still have to get far cheaper to replace more existing cars in order to draw down the greenhouse gas emissions from driving. It will also require a more extensive reimagining of transportation. About 75 percent of vehicle trips in the US are less than 10 miles, which is a huge opportunity for alternatives to driving — cycling, scooters, car sharing, public transit.

So while electric vehicles may be the destination for the auto industry, the road ahead is filled with potholes and detours. Increasing fuel efficiency will make sure carmakers will stay on course.