Final Inspection

U.S. Gets Failing Grade on Fuel Economy


America hasn’t achieved all that much when it comes to conserving fuel – most of us included.

That failure jumps out in black and white in a recently released University of Michigan Transportation Research Institute study on “eco driving,” that shows how much fuel Americans could save, if we made more of an effort.

Using Federal Highway Admin. and other government data, UMTRI calculates average on-road fuel economy in the U.S. for all vehicles at just 17.4 mpg (13.5 L/100 km). That comes against a backdrop of a 27.8 mpg (8.5 L/100 km) light-vehicle CAFE standard in ʼ11 and represents a shockingly low 3.4 mpg (1.4 km/L) gain over an 85-year span.

“Yes, we were surprised, and we wish there would have been more improvement attained since 1923,” notes Michael Sivak, who coauthored the study, Strategic, Tactical and Operational Decisions of the Driver that Improve Vehicle Fuel Economy. “That’s not to say engines didn’t get any better. But some of the extra improvement was used for extra acceleration and power and to carry extra weight.

“As a result, the MPGs are not greatly different now than they were many years ago.”

So what’s the answer?

For one, better driving tactics.

Fuel-economy is negatively impacted by as much as 4% if a vehicle is improperly tuned, another 1%-2% if tires are not inflated to spec and 1%-2% if the right lubrication oil isn’t being used, the study notes.

Traveling the least economical routes – with more traffic, less-than-ideal operating speeds and hilly terrain – can erode fuel economy by double-digit percentages on a single trip, the study says.

In all, drivers can negatively impact on-road fuel economy up to about 45%, meaning a car capable of 36.0 mpg (6.5 L/100) may get only 19.8 mpg (11.9 L/100 km) if the driver does everything wrong. Realistically, Sivak, says, it’s reasonable to expect half that loss could be avoided if drivers became just a bit more econ-conscious.

But the real big impact comes from making the right purchase in the first place, Sivak says.

On average, a car offers 38% better fuel economy than a pickup truck, the study’s authors calculate. The ratio between the highest- and lowest-mileage car is a whopping 9:1.

In addition, choosing the most-efficient version of a particular model – buying the 4-cyl. or V-6 version instead of the V-8, for example – can net an extra 4.3 mpg (1.8 km/L), concludes the report, which UMTRI believes is the first to compare the fuel-saving benefits of driving a more economical car with driving a car more economically.

“Most people view eco-driving to refer only to actions behind the wheel or (involving) vehicle maintenance,” Sivak says. “Our argument is vehicle selection swamps everything else.”

The study, sponsored by a long list of auto makers and suppliers, makes no recommendations on what policymakers should do to ensure America steps up the pace.

But the conclusions seem obvious. CAFE regulations forcing auto makers to build more fuel-efficient cars and trucks haven’t quite produced the desired effect. Something that encourages Americans to buy them might have a bigger impact.

“Anything we can do to encourage people to make the right choice when they go into the showroom would be more beneficial than everything they can do after the sale,” Sivak concludes.

“You can still do a lot if you make the wrong choice. But (that’s) not as important as the first choice you make when you purchase a vehicle.”

Rising gasoline prices appear to have consumers finally headed in the right direction, but whether that trend holds remains to be seen. Let’s hope we at least better the performance of the last 85 years.

What's Final Inspection?

WardsAuto editors share insights and observations on the global auto industry.


David E. Zoia

As Editorial Director, I oversee much of what goes into, enjoying a ringside seat that lets me observe up close just about every facet of the industry worldwide. I have covered the...

James M. Amend

James Amend is an associate editor at, covering day-to-day business and product news at General Motors. He also leads coverage of regulatory and environmental issues, as well as the...
Blog Archive
Follow Us

Sponsored Introduction Continue on to (or wait seconds) ×