Fuel price rollbacks no excuse to drive inefficiently

TheD-MAX pickup and the mu-X SUV are both powered by the RZ4E diesel engine.

If there’s the saying, “money comes and goes,” then we could also say, “prices go up and down.” It’s another way of saying all things–good or bad–will pass. That’s why the latest round of fuel price rollbacks shouldn’t be cause for celebration, because we know those prices will rise up with a vengeance.

So, if the only constant is change, then motorists should always drive on the side of efficiency, disciplined driving that addresses the unpredictability of driving and the transport
industry.

And that’s why I do not pass up the chance to hone this valuable skill. There was a period, years before, when many car manufacturers held fuel efficiency competitions among their customers and buyers, and with motoring media, apart from the usual wheel-to-wheel rallies and races. And it was always the fuel economy competitions that I enjoyed the most, and which, in my opinion, instilled the most discipline among participants.

Isuzu Philippines Corp. has kept that competitive spirit burning in its recent series of fuel economy challenges. And just last August 10, when it held the second leg of its three-part 2019 Isuzu Fuel Eco Challenge Car Club Edition with Team Isuzu Pilipinas (with a mix of satisfied owners of D-MAX, mu-X and Crosswind), I and three of my media colleagues joined in.

We were made to drive either the D-MAX pickup or the mu-X SUV powered by the RZ4E diesel engine developed under the BluePower technology. The RZ4E engine, at 1.9 liters, is Isuzu’s most compact powerplant to date, yet packs a punch: 150 horses and 350 Nm of torque.

IPC engineer Jazon James Y. Sajol, supervisor for the product planning section, told this writer sometime ago that this kind of power from such a small engine has become possible because of a well-designed combustion system that allows high compression ratios to promote efficiency, higher turbo charger pressure, and reduced friction by up to 37 percent in mechanical losses compared to the old 4JK1-TC engine. And with the so-called Dual Exhaust Gas Recirculation system, the RZ4E meets Euro4 emissions
standards.

The route that the fuel economy competition took was short, just four kilometers around the Japanese truckmaker’s Binan, Laguna plant, but it encapsulated quite well the general driving conditions in a city: An enforced speed limit of not more than 40 kph, with lots of stops and gos at intersections, and speed bumps.

In my past drives with the RZ4E mu-X or a D-MAX, my fuel consumption readings were from 14.5 km/liter to 17.1 km/liter on highway runs (depending on traffic conditions and vehicle load).

For this competition, where I was assigned to the D-MAX, I got to replicate my 17.1 km/liter result, enough to clinch me the win for this leg.

These were the pointers shared by IPC technical experts to optimize your fuel efficiency not only with its vehicles, but with any other new vehicles:

1. Avoid engine over-revolution: Gently depress accelerator pedal and use proper gear.

2. Maximize high-speed gear use: As much as possible use higher gear for cruising. For automatic transmission vehicles equipped with manu-matic gearing, use that function to go to the higher gear.

Isuzu PH executives are joined by members of Team Isuzu Pilipinas before the 2019 Isuzu Fuel Eco Challenge.

3. Drive at economical speed. The optimum economical speed may vary from model to model, depending on their engine and transmission systems. But generally, the faster you go, the more wind resistance you encounter.

4. Drive at a constant speed and avoid abrupt braking and accelerating.

5. Use engine brakes effectively. For Isuzu vehicles, releasing the accelerator pedal while the vehicle is in gear automatically cuts off the fuel intake, so you engage engine brakes and consume no fuel at the same time.

6. Minimize idling. Warm up and cool down your engine for only 3 to 5 minutes.

7. Check the tire’s air pressure and follow the tire and car manufacturer’s recommended pressures, depending on vehicle load.

8. Keep your aircon on, but don’t make your cabin too cold. As I have learned from previous economy runs of other car brands, the air conditioner setting, specifically the temperature setting, does affect fuel
efficiency.

9. For safety, don’t shift to Neutral when moving forward. When the vehicle runs on Neutral, you lose connection to your engine, and thus the ability to control it as the need arises.

10. Learn your own engine’s unique torque curve. Some engines are more powerful at the lower RPMs, while others generate more power at higher revs. As one engineer from another car brand quipped: As you learn what RPM range your engine’s power is optimized, so can you orient your driving to that range when you need that power. Your car’s torque range is available in your model’s brochure or from your dealerships.

11. If your regular drive involves mostly city driving in stop-and-go traffic, get a low displacement engine that has a torque curve near the low RPM range.

12. Plan your trip and familiarize yourself with the route to your destination.