What Is the SUV Loophole and Will It Close?

The SUV loophole has existed since the 1970s, but newly proposed environmental rules are bringing it under new scrutiny.

Alexandre Mouravskiy | 

Sep 29, 2023 | 5 min read

 Adobe Stock

As the Environmental Protection Agency (EPA) looks to pass updated emissions and mileage rules for cars built between 2027 and 2032, the so-called "SUV loophole" is under new scrutiny.

The SUV loophole has allowed manufacturers to continue building large vehicles with low gas mileage without getting into trouble with the EPA. Ending it has long been a goal of some environmental groups.

This is a guide on exactly what the loophole is, how it came to be, and what closing it might mean for car buyers.

The SUV Loophole Dates to When Trucks Were Mostly Work Vehicles

Understanding the SUV loophole requires going back to the 1960s in the United States. Automobile and industry pollution had created smog basins around cities including Los Angeles, acid rain was being recognized as a problem, and a newly empowered youth culture put the green movement on the political map.

In response to this pressure, the U.S. government formed the Environmental Protection Agency in 1970 and began drafting regulations to control car pollution. These initial drafts created the foundation of what we now call the SUV loophole: Passenger cars were subject to one set of emissions and mileage rules, and a broad class of vehicles called light trucks were subject to a different set.

This made sense at the time. Light trucks were defined as vehicles with significant carrying capacity not designed for passengers, or with significant off-road driving abilities. At the time, SUVs barely existed as a category. Most light trucks were used by contractors, tradespeople, or farmers, and they made up a tiny percentage of the market.

The newly-formed EPA wanted to avoid penalizing small independent businesses using large, work-related vehicles. At the time, it may have seemed unlikely that regular drivers would want to put up with the hassle and cost of driving and fueling larger cars like light trucks.

Regulations Leave a Space Big Enough to Drive an SUV Through

The EPA's definition of a light truck — technically a "light-duty truck" in EPA parlance — is broad. It's simply a vehicle that might be:

• Curb weight of 6,000 pounds or less(or 8,500 pounds gross vehicle weight rating) with a basic vehicle frontal area of 45 square feet or less — slightly larger than the size of a king size mattress; and
• Designed primarily to transport property, or based on a design that fits this criteria; or
• Designed primarily to transport people with a capacity of 12 or more passengers; or
• Made with special features enabling off-street or off-highway use

At the time the rules were passed, this almost exclusively applied to pickup trucks, commercial vans, and rugged but uncomfortable all-terrain vehicles such as Land Rovers, Jeeps, and Land Cruisers. As technology such as all-wheel drive became more common, the lines began to blur. U.S. manufacturers realized they could face fewer pollution regulations by producing passenger vehicles that were technically classified as light trucks. All they had to do was put a passenger-oriented body on top of an existing truck frame. The resulting SUVs and pickup trucks took off in popularity. The 1984 Jeep Cherokee is often credited as the first modern SUV, and its success didn't go unnoticed. Manufacturers seized upon the SUV loophole to build large cars with less restrictive emissions standards and rake in the higher profits these vehicles generated.

Crossovers Provide Cover for Larger Trucks and SUVs

As emissions standards got tougher over time, a new segment was created to meet consumer demand and help lower light truck fleet emissions and mileage averages: the crossover, or CUV. These were built on the same kind of unibody chassis as passenger cars and were often smaller than traditional SUVs. They also used smaller engines, resulting in higher fuel efficiency and lower emissions.

But because they had higher ground clearance and available all-wheel-drive systems, they could still be classified as light trucks and averaged in with full-size SUVs. This meant manufacturers could keep selling full-size pickups and large three-row SUVs as long as they also sold smaller, more efficient compact crossovers. This is where we currently stand.

Fuel-Economy Standards Tightening, Updated Vehicle Definitions Unlikely

The new EPA draft rules are a move toward bridging the gap between fuel-mileage standards for passenger vehicles and those for light trucks. The draft rules also address some specific governance regarding tailpipe emissions. Under the current rules, tailpipe-emission limits are based in part on vehicle footprint (the total area under the car). Under the draft rules, the classification of those footprint sizes would be adjusted.

The definition of light trucks, however, is unchanged in the draft rules, and it's unlikely that even small crossovers will be reclassified as passenger vehicles.

More Small Cars Could Be Coming — Or Not

Many critics blame the size of SUVs, and the overall increase in the size of cars, for problems ranging from increased pedestrian risk to much higher pollution. Activists and green-policy advocates were hoping that a change in how SUVs are classified might reverse the trend of bigger cars on the road. While the loophole isn't going away completely, the tougher rules may cause some manufacturers to rethink trends and add more small cars to their lineups.

However, it's more likely that the opposite will happen. Americans love SUVs and trucks; even pandemic pricing didn't convince many shoppers to switch to a smaller car. Instead, we've seen manufacturers building even larger electric vehicles, such as the Hummer EV, Ford Lightning, and Ford Mustang Mach-E.

These cars are not only larger, they're also heavier than their gas-powered alternatives. Despite this, they report much higher energy efficiency (rated in MPGe, or miles per gallon of gasoline-equivalent), which can drive down fleet mileage and emissions. And while that might mean cleaner air, it could actually make the roads a more dangerous place for pedestrians and smaller vehicles.

Alexandre Mouravskiy

Alexandre Mouravskiy has worked as a freelance writer for almost 20 years, covering pop culture, politics, and automobiles. He’s written about road tripping across the eastern seaboard, replacing broken wheels in a blizzard as an amateur rally navigator, and once drove from the Gulf to the Hudson Valley in a single day. When he’s not writing, Alexandre can be found wrenching on one of his project cars or teaching people to drive stick, whether they want to learn or not.