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Adjusted fuel consumption ratings: All you need to know

As you know, the current fuel consumption ratings are difficult to achieve for most drivers, even with moderate use of the throttle and air conditioning.

Therefore, Natural Resources Canada (NRC) recently announced a new protocol to determine fuel consumption ratings, starting with 2015 model year vehicles. This way, the average driver will have a better idea of much fuel they can expect to burn day in, day out.

Current testing
Fuel consumption ratings are derived from the emissions generated during two laboratory driving cycles: a city test and a highway test.

According to NRC, the city test simulates urban driving in stop-and-go traffic with an average speed of 34 km/h and a top speed of 90 km/h. The test runs for approximately 31 minutes and includes 23 stops. It begins from a cold engine start, which is similar to starting a vehicle after it has been parked overnight during the summer.

The final phase of the test repeats the first eight minutes of the cycle, but with a hot engine start. This simulates restarting a vehicle after it has been warmed up, driven, and then stopped for a short time. Over five minutes of test are spent idling to represent waiting at traffic lights.

Meanwhile, the highway test simulates a mix of open highway and rural driving, with an average speed of 78 km/h and a top speed of 97 km/h. The test runs for approximately 13 minutes and does not include any stops. It begins from a hot engine start.

The fuel consumption values derived from these test cycles are then adjusted upwards by 10% (city) and 15% (highway) to more accurately reflect real-world driving.

New testing
Here, the standard 2-cycle test program is supplemented with three additional tests that account for cold temperature operation, air conditioning usage, and higher speeds with more rapid acceleration and braking. This 5-cycle testing procedure better approximates typical driving conditions and behaviours.

In the cold temperature operation test, the same driving cycle is used as in the standard city test, except that the ambient temperature of the test cell is set to -7°C.

In the air conditioning test, the ambient temperature of the test cell is raised to 35°C. The vehicle's climate control system is then used to lower the internal cabin temperature. Starting with a warm engine, the test averages 35 km/h and reaches a maximum speed of 88 km/h. Five stops are included, with idling occurring 19% of the time.

Finally, the high speed/quick acceleration test averages 78 km/h and reaches a top speed of 129 km/h. Four stops are included, and brisk acceleration maximizes at a rate of 13.6 km/h per second. The engine starts warm, and air conditioning is not used.

What about 2014 and older vehicles?
While the new testing procedure starts with 2015 model year vehicles, NRC has developed an interactive tool for owners of 1995-2014 vehicles who would like to get their adjusted fuel consumption ratings.

Some will feel that the new ratings are too high, while others will find them too optimistic. Keep in mind that these are average ratings with numerous variables.

Here's a comparison:

ClassMake and model
Current ratings
City/Highway (L/100km)
Adjusted ratings
City/Highway (L/100km)
Sub-compactNissan Versa6.1/4.87.2/5.8
CompactHonda Civic6.7/5.07.9/6.0
MidsizeFord Fusion (2.0L)9.2/5.910.5/7.1
Full-sizeHyundai Sonata (2.0T)10.0/6.311.4/7.5
Pickup truckChevy Silverado (4.3L)11.9/8.413.4/9.9
SUVMazda CX-5 (2.5L)8.3/6.29.6/7.4
MinivanDodge Grand Caravan12.2/7.913.7/9.4

How to achieve these ratings
There is no miracle solution to significantly improve your fuel economy. However, you can make a number of changes to your driving habits. NRC suggests these five basic fuel-efficient driving techniques:
  1. Accelerate gently;
  2. Maintain a steady speed;
  3. Anticipate traffic;
  4. Coast to decelerate (whenever possible)
  5. Avoid high speeds
Source: Natural Resources Canada

Also, remember that short trips considerably increase your fuel consumption. So, run your errands one after the other, planning your route to avoid backtracking and rush-hour traffic. The longer trips will enable your engine to warm up to the temperature at which it converts energy most efficiently.

The NRC website is full of detailed tips and information about efficient driving and the new testing procedure -- make sure to check it out. You don't need to become a hypermiling expert or travel at 80 km/h on the highway to achieve the posted fuel consumption ratings; a bunch of small changes to your driving habits can literally go a long way.

What's your take on NRC's adjusted fuel consumption ratings? We're curious to find out!

Source: Natural Resources Canada