Honda Cars Philippines, Inc. just released fuel efficiency information about the 2023 Honda BR-V, its soon-to-be-launched seven-seater MPV. 

According to HCPI, a three-way fuel efficiency run featuring the all-new Honda BR-V was conducted in partnership with the Automobile Association Philippines (AAP), which observed the conduct of the test. And the results are as follows:

• 24.70 kilometers per liter for the 1.5 V CVT variant
• 23.48 kilometers per liter for the top-of-the-line 1.5 VX CVT Honda SENSING 
• 22.61 kilometers per liter for the 1.5 S CVT 

The test parameters saw the cars travel 128 kilometers with the following parameters:

• No cruise control
• Driving with an average speed of 70 to 80 km/h
• Low cool in the thermostat setting, Number 1 for the blower setting

Since it's a press release, we can call it a day after reporting the results. But that would be a disservice to you, our readers, because you need to know how these factors can potentially affect the results of any fuel economy run. 

I've been part of several similar events over the years, and if there's one sure thing, the results of fuel economy runs can vary due to many factors. Time of day, distance, driver throttle application, traffic, road elevation, number of passengers, and tire pressures can all alter the results.

It doesn't help that the Department of Trade and Industry, the Department of Environment and Natural Resources, the Department of Energy, or even the Department of Transportation have not implemented any fixed standard on how the fuel efficiency of vehicles sold in the country should be measured and documented. And when gasoline and diesel costs are skyrocketing like they are today, fuel efficiency information is essential to making the right choice of vehicle.

Think of it as the government-mandated Energy Efficiency Ratio label on the air conditioning unit you are considering buying. The higher the number, the more likely you'll purchase the unit, as it will save you pesos operating the appliance versus another model with a lower EER number. What if cars had that plastered on their windshields on the showroom floor? Wouldn't it help you make a better decision?

But since we don't have a uniform standard yet, why don't we see how the fuel economy runs observed by the AAP are done and why the manufacturers chose the parameters above in the test runs they oversee? And to further clarify, the AAP does not run the event. The manufacturers provide the vehicles, assign the drivers, and set the route and time of the tests. The AAP joins it to check and double-check that the agreed-upon parameters are adhered to.

No cruise control

The basic cruise control function of any car hands over the throttle application to the vehicle. Based on the speed set by the driver, the car will maintain the set speed without the need for the driver to step on the accelerator. In theory, it should produce a more consistent speed on flat roads. But as soon as the road elevation rises, the system will apply more throttle to keep the vehicle at the set speed. This, in turn, will use up more fuel.

It becomes more complicated when Adaptive Cruise Control is included, as with the 2023 Honda BR-V. If the system detects the shortening distance to another vehicle in front, it will automatically slow down the car to maintain the preset distance. It will automatically accelerate again once the vehicle in front opens the gap. 

Now, why is this not used in fuel economy runs? Any time the car decelerates and accelerates after, the vehicle will consume more fuel to return to the set speed. In this case, 70 to 80 km/h. Had the test allowed cruise control to be activated, it would possibly interfere with the driver's objective of maintaining a constant speed with light and steady throttle application to achieve maximum fuel efficiency. So to eliminate the variances, Honda decided not to use the system. 

Driving with an average speed of 70-80 km/h

To be clear, what the drivers really need to achieve during fuel economy runs is to maintain the highest speed possible at the lowest engine speed or RPM possible. That also means the minimal use and movement of the throttle pedal. This ensures no additional fuel is fed to the engine while keeping to a set speed.

By having a degree of variance in road speeds, the drivers of the cars in these fuel economy runs can keep a steady and light pressure on the accelerator pedal even when the road's elevation rises. So even if the speed drops to 70 km/h, they are still within the test parameters and don't have to open the throttle body any more than they have to to keep that speed. 

Furthermore, when the road descends, drivers can lift off the throttle pedal and coast in gear as long as they are within the 70-80 km/h range, further saving fuel. If you've been driving a modern-day car, you'll notice when coasting in gear; the fuel consumption display shows 999.9 km/l. This means fuel flow to the engine via the fuel injectors has been disabled when coasting in Drive and the engine is turning because it of it is connected to the driven wheels when in gear. But as soon as you try the old method of coasting in neutral, the system will continuously feed fuel to the engine to keep it idling. Thus you end up using more fuel. 

But why 70  to 80 km/h? Here is where aerodynamics comes into play. To move a car at a certain speed requires effort (and fuel) from the engine. Beyond a that speed, however, the car uses more fuel to overcome air resistance. Modern vehicles usually cruise comfortably at low RPMs, around 1,500 revs nowadays, and anywhere from 80 to 90 km/h. But that comfort zone is also dependent on the gearing of the transmission. The good thing about the Honda BR-V with its Continuously Variable Transmission is that it can automatically decide to match the drive ratio with the vehicle speed to achieve the lowest RPM. 

Furthermore, Honda, as with most manufacturers in the country, adopted the Department of Energy's fuel economy run test parameters back when the agency used to do them in cooperation with Petron a few years back. And all the AAP observers have to do is check if Honda's drivers comply with the preset conditions.

Low cool in the thermostat setting, Number 1 for the blower setting

Running the air conditioning unit of any car adds load to the engine. With more load, the engine needs to compensate by raising the RPM to ensure smooth, shudder-free operation. And by increasing the RPM, the engine uses more fuel. 

In addition, the colder you set the thermostat, the more times the A/C compressor needs to run to maintain the cool temperature. And we go back to the previous paragraph. 

Low cool is the lowest thermostat setting in most cars nowadays. It's turning down the thermostat knob or switch all the way down. This way, it is more consistent and uniform across all vehicles participating in the test. It is not based on a specific temperature which sensors may read differently. And by setting the blower to number 1, the minimum operating speed for the fan is made consistent across all cars. Again, consistency is the key to providing more consistent results with minimum impact of external factors. 

So, how reliable are the results?

These results are very reliable given the parameters of the fuel economy run. The Honda BR-V can and will likely achieve repeatable results with these three specific guidelines. But two things should come into consideration when interpreting these results. One is driver skill.

A driver with a light foot who knows how to conserve momentum will generally outperform a driver with lesser abilities or hardly a care of what the fuel economy run test entails. And we dare to suggest that the variations in results among the three vehicles with similar drivetrains were primarily due to driver input.

Second is the driving conditions. To achieve these numbers, car manufacturers would typically do their fuel economy runs on highways, where there is less traffic. Others would even hit the road in the wee hours of the morning to ensure minimal cars interfere with the drive and low ambient temperatures to minimize the activation of the A/C compressor. Both these two factors can severely affect the mileage of a vehicle. 

Run any car in Metro Manila traffic during rush hour, and you'll struggle to get any vehicle to achieve 10 kilometers per liter. And many trips are usually a mix of city and highway runs, further complicating any fuel economy test attempt. There are just too many variables that will affect the results when done in real-world conditions.

And this is where the careful assessment of the test parameters is crucial. When you are on the showroom floor, and the sales agent claims the car he sells can do 25 kilometers per liter, ask how the number was achieved. Know the parameters of the test and the conditions of the run. Understand that the fuel economy numbers brandished at the showroom, and it does not matter which brand it is, are all based on specific requirements you will have to achieve to replicate the results.

The car can achieve those numbers, sure. But will it do so all the time? That's another story.