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Fuel Economy Hasn’t Much Changed Since 1923

Or has it? Federal data leaves some big gaps open.

by on Aug.20, 2015

New study suggests that today's auto fleet isn't getting much better mileage than it did 90 years ago.

Federal guidelines are calling for some big increases in fuel economy over the next decade, with the average vehicle required to deliver 54.5 mpg by 2025.

But a new study by the University of Michigan Transportation Research Institute, or UMTRI, adds a cautionary note to that push, noting that from 1923 to 2013, the average mileage of the American automotive fleet rose a meager 3.6 miles per gallon, to just 17.6 mpg.

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In fact, fuel economy actually tumbled for a number of years, only starting to rebound in 1974, in the wake of the first Mideast oil shock as Washington enacted the first Corporate Average Fuel Economy, or CAFE, standard.

Initially, mileage “increased rapidly” after the new mandate went into effect, noted study authors Michael Sivak and Brandon Schoettle. But in recent years, they added, “improvements have been small.”

(Better mileage is one reason SUVs and CUVs are gaining sales. Click Here for the full story.)

Until the 1970s, fuel efficiency was low on the radar screen for most American motorists, and not something the auto industry worried about. As a result, mileage that averaged 14.0 mpg in 1913 actually tumbled to just 11.9 mpg by 1973, according to the study.

Congress enacted the CAFE standard in 1974, but it only began to have an impact with the start of the 1978 model-year. By 1991, mileage had rebounded to an average 16.9 mpg. But by 2013, it had improved only another 0.7 miles per gallon, to 17.6 mpg.

That might suggest that the auto industry is going to have to pull out all the stops to get to the daunting 54.5 mpg standard set for a decade from now. But the numbers aren’t quite what they seem. For example, the 2025 target includes a number of credits and adjustments. In real-world terms, the average vehicle will only have to get into the low-40 mpg range to comply with CAFE.

And that figure applies only to new vehicles sold starting in 2025. The UMTRI study actually looks at the average fuel economy of all of the vehicles on the road, nearly 300 million today and growing.

(Next-gen Toyota Prius likely to see a 10% jump in fuel economy. Click Here for more.)

“One fundamental problem with improving the fuel economy of the entire on-road fleet is that (it can) take a long time…because it takes many years to turn over the entire fleet,” wrote Sivak and Schoettle.

Indeed, a separate study released last month by Experian Automotive found that the typical vehicle on the road today is more than 11 years old, an all-time record. Millions have been in use since the 1990s.

The UMTRI study, meanwhile, requires some careful examination. In the early years, federal data rolled in all motor vehicles. So, from 1923 to 1935, the figures included everything from motorcycles to heavy trucks. From 1936 to 1965, the feds separated cars and trucks, though motorcycles were lumped into the passenger car category. Only in 1966 did the Department of Transportation finally start to break things out by weight class, as well.

If you go back and parse the data, it turns out, cars turn out to have tumbled from 15.3 mpg to 13.4 between 1936 and 1974, but the number jumped to 23.4 mpg by 2013, a much more substantial improvement than for the overall U.S. fleet.

The big problem has been on the truck side. As they grew bigger and more powerful, taking on ever heavier loads, medium and heavy-duty trucks saw marginal gains of a mere 0.8 miles per gallon from 1966 to 2013, reaching a mere 6.4 mpg.

New federal rules are taking aim at those big trucks and could see major improvements in the years ahead. Considering the miles an 18-wheeler can clock in a typical year, measured in the 10s, and often 100s of thousands, the trucking industry says the payoff can be substantial and can come much quicker, in terms of return-on-investment, than with a passenger car.

(British highway project could end EV “range anxiety.” Click Here to find out how.)

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4 Responses to “Fuel Economy Hasn’t Much Changed Since 1923”

  1. Jorge says:

    The trucking industry has been working on better fuel economy for over 20 years and some gains have definitely been made. Class 8 HD trucks all use clean Diesel engines because they are more practical and dramatically more fuel efficient than gasoline engines of similar displacement, while delivering superior torque and lifespan over gas powered engines.

    The U.S. has the most stringent Diesel engine emissions requirements in the world because Obama and the EPA want people to buy impractical EVs. The rest of the world uses clean Diesel power for most applications including almost all trucks and as much as 75% of passenger cars where they easily obtain 50+ mpg. The recent U.S. government mandated Diesel emissions changes for both large and small Diesel powered vehicles lowered fuel economy and raised the cost of these vehicles substantially.

    Class 8 truck and engine makers have been making good improvements in aerodynamics and combustion technology to recover some of the losses from the absurd U.S. Diesel emissions requirements intended to hurt the populace. The cost of Diesel fuel being higher than regular gas illustrates how the oil industry Cabal is doing their part to rape consumers. We all pay for these inappropriate political decisions by the clowns in DC and by the exploitation from the oil Cartel.

    • therr says:

      I agree. In 2003 I bought a Ford Superduty with a 6.0L diesel. In 2004 I took it in for a recall to reprogram the ECU because particulate emissions were too high. Before the recall I was getting 18.5mpg. After the recall I could not get over 15.3mpg no matter what I tried or how I drove. How are the big rigs suppose to do better if every improvement is met with tighter restrictions? They do haul heavy loads after all and moving weight takes more power and more fuel.

  2. DWH says:

    Jorge just how much is somebody paying you to spread proproganda about technology? In europe tier 4 is tougher than the usa. If you would talk the facts instead of injecting political bs your lack of objectivity of the the automobile industry. If you are working for some corporation trying to make something or someone look bad. Your going to have to up your game, meaning data. It would have worked on people fifty years ago. Not now.

    • Jorge says:

      As usual DWH you are wrong again. I work for no one involved in any of these discussions and I don’t sugar coat the truth. As Paul, I and other folks here have educated you in the past, your beliefs are not based in reality. Your shilling of EVs to drive stock prices up is unscrupulous. Your problem is that you can not handle the truth.

      As I previously suggested, instead of making these discussions personal, you might better go to a forum where you can dupe people with your meritless and technically incorrect assertions because what you’ve stated here has been wrong over and over. Attacking the messenger does not change reality.