EPA Label

Why the generic sticker label can be inaccurate

  |   Hybrid Vehicle   |   No comment

Many many years ago, in the 70’s – NRCan decided to measure fuel economy. There were only two test cycles involved to generate these numbers: 1 highway, 1 city.  The drive cycles measured fuel consumption values from derived emissions generated through laboratory tests.

The simulated city cycle test runs for approximately 31 minutes with an average speed of 34 km/h and a top speed of 90 km/h. The test assumes there is stop-and-go-traffic, so there are exactly 23 stops within the span of 31 minutes, around 5 minutes of the test time is spent idling as a representation of traffic lights. This test has one cold engine start and a repeated final phase with 8 minutes of hot engine start.

The simulated highway cycle test run for approximately 13 minutes with no stops. It includes a mixture of rural roads and highways at a speed of 78 km/h to a top speed of 97 km/h. This test cycle only has a hot engine start.

After these cycles have been completed, they are adjusted by 10% for the city cycle and 15% for the highway cycle.

city and hwy

When you drive around a city do you stop exactly 23 times? What is the average speed you drive when you’re on the highway? In the city? These lab tests don’t account for any realistic errors on road such as highway traffic. Or for different city environments– we know driving in Toronto is not the same as driving in Mississauga and is not the same as driving through small towns.

The outdated lab tests also does not account for an idling factor that varies upon different seasons. From our data we recognized that most people will idle more in winter months, and less during the summer. The difference in idling can be up to a 10% difference, winter idling can be around 21-25% and summer idling can be around 16-18%.

Since the data was created in the late 70s, there have been many changes to road regulation including the speed limit. Average city speeds can vary from 40-70 km/h and average highway speeds can vary from 100-120 km/h.

The many obvious advantages of personal fuel economy shows the impact of the average drive cycle you take and your personal driving behaviour. Since the current fuel economy stickers are based off lab results, it is not a realistic way of understanding how much you spend on gas and can save on gas a year depending on the vehicle you drive.

See what your personal fuel economy is, get your MyCarma report today!






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