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Why the EPA’s Vehicle-Size Classes Make No Sense

If you’ve heard or read terms like “subcompact,” “mid-size,” and “large” bandied about for various cars and found yourself at times wondering what, exactly, puts any given car into one of those buckets, you’re not alone. There are many ways to classify car sizes, from weight to exterior dimensions to interior volume. The EPA takes the latter path, not for its emissions regulations, but for its fuel economy reporting.

OK, so interior volume—that seems like a reasonable measure of a car’s size, right? To have a large interior volume, a car would presumably have to have an exterior size large enough to enclose it, and that should scale from small to large in a pretty intuitive fashion, right? Well, sort of. But before we get into why it’s only “sort of,” let’s take a look at the classes as they sit now:

EPA Sedan Size Classes by Interior Volume (Passenger and Cargo Volume Combined)

  • Minicompact: Less than 85 cubic-feet
  • Subcompact: 85-99.9 cubic-feet
  • Compact: 100-109.9 cubic-feet
  • Mid-Size: 110-119.9 cubic-feet
  • Large: More than 120 cubic-feet

That seems pretty clear-cut, although your attention may immediately be drawn to the borders between classes—it hardly seems fair that a car a mere 0.1-cubic-foot larger than another may be forced into the next higher weight class. On the other hand, you have to draw the line somewhere.

Speaking of drawing the lines, you might note the classes above are only for sedans. That’s right, station wagons have an entirely different set of sizes, too, even if Americans hardly buy them anymore:

EPA Station Wagon Size Classes by Interior Volume

  • Small: Less than 130 cubic-feet
  • Medium: 130-159 cubic-feet
  • Large: More than 160 cubic-feet

OK, again, some clear-cut divisions, though it’s worth noting that even the smallest station-wagon class has an entire small trunk’s worth of extra space compared to the entry point to the largest sedan class. That seems a bit odd, given that a typical station wagon is just a sedan with a boxed-in rear cargo area in place of the notch-and-trunk layout of its four-door cousin. But we’ll let that slide for now, because things get weird when classifying trucks, which use weight as the determining factor rather than interior volume.

Interior volume, of course, doesn’t work as well for trucks, because they have beds, right? Right, except the EPA also classifies SUVs, vans, and minivans as trucks for some reason—and all three are, by definition, entirely enclosed vehicles. So why are these vehicles lumped in with pickup trucks and classified by weight? There’s the cynical answer (auto industry lobbying to make it easier to meet fuel-economy targets) but that’s only part of the explanation. Another part of it is that SUVs and vans, at least, are, or at least were, typically based on pickup trucks. In today’s world of car-based crossovers, however, that’s a historical artifact, not a good justification—and it never really applied to minivans at all.

But regardless of why the EPA’s “truck” size classes are the way they are, they make surprisingly little sense. Whereas the cars and station wagons are divided into 10-cubic-foot segments, the “trucks” are given high and widely-spaced Gross Vehicle Weight Ratings (GVWR), even in the smallest categories.

EPA “Truck” Size Classes by Gross Vehicle Weight Rating

  • Pickup Trucks
    • Small: Less than 6,000 pounds
    • Standard: 6,000-8,500 pounds
  • Vans
    • Passenger: Less than 10,000 pounds
    • Cargo: Less than 8,500 pounds
  • Minivans
    • Less than 8,500 pounds (one size fits all)
  • Sport Utility Vehicles (SUVs)
    • Small: Less than 6,000 pounds
    • Standard: 6,000-10,000 pounds

The use of GVWR instead of actual vehicle weight means the load each vehicle is intended to carry, as well as its own weight, determines the classification—so maybe it does make sense?

Maybe, except we’re talking about GVWR, rather than GCWR (Gross Combined Weight Rating), meaning it’s not about towing capacity, but about what you can fit into the vehicle itself. Alright, fair enough—but in the case of SUVs and minivans, at least, there’s no substantive difference in payload types from what you can stuff into a sedan or a station wagon except for the maximum exterior dimensions of any given object. In other words, you could load a sedan or a station wagon full of people, or jugs of milk, or bags of mulch, just the same way you would other passenger vehicles like SUVs or minivans. These aren’t pickups with a half-ton of gravel in the bed.

So now that we have a handle on exactly what the EPA’s size classes are, let’s have a look at some of the more ridiculous groupings in the 2020 model year. If these oddball groupings of cars make good and obvious sense to you, congratulations! You have a bright future at the EPA.

“Minicompact” Cars, According to the EPA:

  • Aston Martin DB11
  • Bentley Continental GT Convertible
  • Ferrari GTC4Lusso
  • Polestar 1
  • All Porsche 911s

“Subcompact” Cars, According to the EPA:

  • BMW M4
  • All Chevrolet Camaros
  • All Ford Mustangs (except Mach-E)
  • Karma Revero GT
  • Lexus RC F
  • Mercedes-AMG A35
  • Mercedes-AMG C43
  • Mercedes-AMG C63
  • Mercedes-AMG E53
  • Nissan GT-R

“Compact” Cars, According to the EPA:

  • Acura TLX
  • Audi A4
  • BMW 3-Series
  • Chevrolet Sonic
  • Lexus GS F
  • Mazda 2
  • Mercedes-Benz CLS
  • Mercedes-AMG GT 4-Door
  • Mitsubishi Mirage
  • Rolls-Royce Dawn
  • Volvo S60

“Mid-Size” Cars, According to the EPA:

  • Audi A6/S6
  • BMW 5-Series
  • BMW 8-Series
  • BMW X2
  • Bentley Flying Spur
  • Bentley Mulsanne
  • Dodge Challenger Widebody
  • Lexus GS 350
  • Lexus LS
  • Nissan Altima
  • Nissan Kicks
  • Rolls-Royce Wraith

“Large” Cars, According to the EPA:

  • BMW X1
  • Honda Civic 5-Door
  • Honda Accord
  • Hyundai Elantra

“Small” SUVs, According to the EPA:

  • Acura MDX
  • Buick Encore
  • Ford EcoSport
  • Jeep Wrangler Unlimited
  • Honda CR-V
  • Honda Pilot
  • Range Rover Velar
  • Toyota Highlander
  • Volkswagen Atlas

“Standard” SUVs, According to the EPA:

  • Audi e-tron Sportback
  • BMW X7
  • Cadillac Escalade
  • Chevrolet Tahoe
  • Ford Explorer
  • Bentley Bentayga
  • Land Rover Defender 90
  • Lexus RX

The post Why the EPA’s Vehicle-Size Classes Make No Sense appeared first on Automobile Magazine.