Corporate Average Fuel Economy Reality
Would it surprise you to know that in 1980 when the average Corporate Average Fuel Economy (CAFE) for cars was about 25 miles per gallon, actual on-road economy was about 16 mpg? Or that in 1990, when the average CAFE for cars was 28 mpg, the actual on-road economy for them was only 20 mpg? Even in 2000, the CAFE average for cars was still around 28 mpg, but on-road economy was just 21 mpg. Those are numbers the Federal Highway Administration (FHWA, on-road data) has as compared to the annual reporting of the National Highway Traffic Safety Administration (NHTSA) for CAFE figures. These numbers are just for passenger cars - they get worse with light trucks.
Would you also be surprised to learn that the current standards promoted by President Obama and recently finalized and released, conveniently, during the Republican National Convention in Florida, are actually numbers first proposed and initiated in policy by former President George W. Bush back in 2007? Yes, an evil, oil baron Republican initiated the first, tougher CAFE requirements in over two decades, not the current guy taking credit for it. That might give some recent commentators pause.
Whether it's a Republican or a Democrat (I prefer the terms "Republicrat and Demopublican" myself) that initiates CAFE, though, the fact remains that what is advertised is not really what is being provided. Of course, false advertising is the standard in Washington.
The 7-9 mile per gallon disparity between the CAFE requirement and the actual on-road efficiency of cars is easily explained once you understand how the Corporate Average Fuel Economy scheme actually works. Once you understand that, you'll see why automakers didn't really argue that hard against these newer requirements. In another segment (find it here), we look even deeper and see why it is that setting up more stringent CAFE requirements doesn't change anything worthwhile (despite the promises), but it costs us plenty when we do it.
How CAFE Is Measured vs EPA Sticker Measurements
Every new car on the lot has a window sticker that those in the business call a Monroney. This is a standardized sticker showing the costs, package inclusions, and so on for the car in question. Part of that sticker is the easily-recognized Environmental Protection Agency (EPA) mandated fuel economy graphic. This shows the city, highway, and average fuel economy numbers in miles per gallon for the vehicle, according to EPA testing.
These numbers are very different from CAFE numbers, which are administered by the NHTSA.
When the NHTSA tests a vehicle for CAFE mpg, it puts it on rollers, gets it up to 55 miles per hour, and then measures its fuel consumption. Nobody is in the car, no changes in highway conditions or speeds are given, and nothing from the real world is affecting the car. The consumption it has under these conditions is its CAFE mpg.
When the EPA tests a vehicle for mpg, it uses a series of tests that include the weight of the driver in the car and that attempt to mimic real-world conditions. Highway speed is measured, then city speeds, and things are thrown in the mix to simulate stop-and-go traffic and the like. From here, the highway mpg and city mpg are calculated. Then the average American's drive is simulated as a 60/40 split between city/highway driving and from that the average of the two is calculated.
Why 54.5 MPG Is Just a Headline
Given the above information, you can see that if that was all there was to it, then the advertised 54.5 mpg would actually be closer to 47 mpg or so. If that was all there was to it.
First, the 54.5 mpg is actually not in the CAFE requirements at all. It's a projection, not a set standard. More on that in a moment.
The new NHTSA CAFE standards are in two parts, since the EPA's mandate for CAFE only allows them to set rules for five model years at a time and with updates, the agency usually offers five years of requirements followed by an additional five years of expectations. Most of the time, the news media sees this as just ten years of mandates and since big numbers make headlines, they go with the biggest. More often than not, the politicians and back-patters involved will encourage this assumption.
In the current CAFE standard just finalized, model years 2017-2021 are mandated while model years 2022-2025 are proposed (aka "augural" and based on the EPA's "best estimates"). This means that the only thing that matters, really, are the requirements up to 2021 (the government is also required by law to give five years' time before implementation). Actual CAFE requirement for cars in model year 2021 is 40.3 mpg to 41.0 mpg.
So where did this much-touted 54.5 mpg number come from? Well, a second part of the CAFE standard is in regards to CO2 emissions restrictions by the EPA. In the proposed augural projections, CO2 emissions would be restricted to 163 grams per mile. If automakers met that purely by improving fuel efficiency, then they would have to achieve 54.5 mpg.