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What?s a fuel rating worth when it?s wrong?

One recent morning ? cool but not cold ? I headed east across Toronto in a Ford Fusion hybrid.

My 20-kilometre route covered traffic-clogged College and Carlton Streets to Gerrard, then, out to Woodbine Ave. and back west along the more open Eastern Ave. and Lake Shore Blvd. to the CNE. I drove sedately.

What?s so special about this little jaunt?

Simple: The U.S. Environmental Protection Agency rates the Fusion hybrid?s gasoline consumption at 47 miles per gallon, or five litres per hundred kilometres. Transport Canada, using laughable test procedures, calls it just four.

Last week, citing the EPA results, the American Council for an Energy-Efficient Economy ranked the Fusion hybrid, and sibling C-Max, among the 12 greenest cars of 2012. Earlier, the figures helped the entire Fusion family ? hybrid, plug-in and conventional internal-combustion ? become the Green Car Journal?s Green Car of the Year.

But whoa! After my urban drive, the ?SmartGauge? dashboard display showed 8.9 litres per 100.

Not all the readings in my test Fusion, a comfortable and plenty-powerful mid-size sedan, were so far out of whack with the official figures. On a mostly highway drive to Lake Simcoe, it averaged an excellent 5.5 litres per 100. But from the CNE to mid-Mississauga, along the Gardiner Expressway/QEW and arterial roads, it scored seven ? 40 per cent above the EPA number.

The EPA and Transport Canada advise that, because consumption varies with driving conditions and styles their results are best used to compare competing models.

Still, the numbers are important not just for marketing but also for assessing progress toward fuel efficiency, environmental benefits and energy security. If the test scores swing wildly depending on where and how a car is being driven, and the gap between official and real-world consumption varies significantly among different vehicles, then, what?s the point?

Carmakers conduct the EPA tests on dynamometers in laboratories. The agency spot-checks a few. Top speed in the 16-kilometre highway cycle is 96 kilometres per hour; the average, just 78.

I?m far from alone in questioning the resulting numbers.

Consumer Reports claims its tests indicate the Fusion hybrid burns six litres of gasoline per 100 kilometres of urban/highway driving ? 20 per cent more than the EPA?s figure.

Its highway test is a constant 104 kilometres per hour on a real road. But with little acceleration or deceleration, it?s nearly as unrealistic as the EPA?s.

A recent report from the European Commission concludes one-third of the improvements there came from carmakers manipulating ?flexibilities? in test procedures.

The electric-vehicle advocacy group Plug In America complains the EPA tests, too, are open to manipulation.

Ford faces a U.S. lawsuit, based in part on issues with the EPA tests.

The Detroit News cites one explanation, starting with the low top speed in the highway test. Ford hybrids can operate at up to 99 km/h on battery alone if driven exactly as the EPA prescribes. Over 99, the gasoline engine starts and fuel economy drops.

So the test score essentially over-emphasizes electric-only driving, since most American major highway limits are at least 105, and few drivers cruise below that.

I?ve asked the EPA about this critique, and for details of a promised review. Spokesperson Cathy Milbourn says only: ?we really can?t answer these questions now. We are just looking at this.?

At Ford Canada, communications manager Christine Hollander notes for fuel economy, ?there are lots of variables ? it is hard to evaluate.?

My Fusion hybrid test produced impressive fuel-economy scores under some circumstances. But as with other ?efficient? cars I?ve tested, the results are too variable and uncertain for judging policies or benefits.

OK, I?m repeating myself from previous columns: But if the numbers are to have more than entertainment value, we need a better way to produce them.

  • What?s a fuel rating worth when it?s wrong?
  • What?s a fuel rating worth when it?s wrong?
  • What?s a fuel rating worth when it?s wrong?

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