INTRODUCED in March this year, Isuzu’s new RZ4E 1.9-liter turbodiesel motor is its manufacturer’s response to the global trend when it comes to producing engines with smaller displacement yet still capable to yield substantial output. Intended as a direct replacement to the ever-reliable 4JK1-TC (Hi) 2.5-liter mill, the new RZ4E engine remarkably offers higher output compared to its predecessor. Generating 148 horsepower and 350 N-m of maximum torque, this new powertrain even weighs lighter by 60 kilograms, which contributes to better power-to-weight ratio. But the secret to the impressive output ratings lies in various technological advancements adapted from four years of extensive research and development.
In order to validate the new powertrain’s better performance and outstanding fuel efficiency, Isuzu Philippines Corp. (IPC) recently invited select members of the motoring media for a unique ride-and-drive experience dubbed as “Isuzu Driveway Getaway 2018.” Commissioned for the event were several of Isuzu’s newly launched 2018 D-Max LS and mu-X LS-A 4×2 variants—both fitted with the new-generation diesel motor.
Started in an early-morning assembly at Petron Marilao service station along North Luzon Expressway, we were grouped into teams for the initial challenge. The objective was simple—to consume the least amount of fuel for a 112-kilometer run from Petron Marilao to Petron Tarlac along Tarlac-Pangasinan-La Union Expressway. But the method to measure the result was through Isuzu’s state-of-the-art diagnostic tool. It’s the Global Isuzu Diagnostic Service System (G-IDSS), which scans all data parameters from the Electronic Control Module, Transmission Control Module, Anti-lock Braking System and Immobilizer System.
The car-like interior now has more refined trims, adding more details to the dashboard and sidings. Notably, aside from the touch-operated infotainment system equipped with connectivity functions, there are more 12-volt sockets and USB terminals for the passengers to utilize. Moreover, there are more cup holders and multiple storage compartments. Maintaining an 80 kph speed most of the time, everything was tranquil inside until we reached the final stop almost two hours later. There, no less than IPC technical adviser of sales division Taro Unai administered the final tests in each team utilizing the G-IDSS, but the official results were yet to be announced later on.
En route to the country’s surfing capital
After the final tests, we resumed the drive to further test the new engine’s performance. Behind-the-wheel, the acceleration was evidently unrelenting as reaching the high speed limit was steady and swift. While traversing the remaining stretch of TPLEx, the final gear only remained below the low end rev range. But what was remarkable was how quieter the engine compared to its predecessor.
With comfy seats adjusted to the perfect driving position, everything else became smooth and relaxing. Even while intentionally varying the speed ranges, the new motor effortlessly picked up the pace with very minimal changes in the rev range. Momentarily, we reached the highway exit and proceeded to our lunch stopover. Resuming the drive, this time along the provincial highway, it was the perfect opportunity to validate the RZ4E’s ability to handle the demands of overtaking.
Every time the situation calls for it, the vehicle just went on without any hesitation. We were amazed with the response coming from a 1.9-liter mill in hauling the pickup’s large frame. There was no need to manually downshift the six-speed automatic gearbox with sequential shift mode. Just step on it, and the throttle response will do the rest. Unquestionably, this new RZ4E motor does the job done and perfectly suits the 4×2 setup in favor of better fuel efficiency and yet still substantially responsive.
As we went on to pass every slow vehicle while catching up with time, we managed to conclude the 254-kilometer drive and made it to the Thunderbird Resort in Bauang, La Union in the afternoon and settled.
Outstanding fuel consumption
During the introduction of the 2018 DMAX, the eco-challenge results verified by the Automobile Association of the Philippines recorded outstanding figures. Considering the realistic approach in driving along the freeway, our team registered the best calculation at 22.59 km/l (4.96 liters in 112.05 km) in the DMAX category. The mu-X category winning team, on the other hand, registered best at 23.28 km/l.
IPC President Hajime Koso lauded the participants for their driving skills and discipline in maximizing fuel efficiency. “The astounding fuel mileages that all of you got from this economy run, most especially of those who won the challenge, only proves that the right combination of good driving habits and the efficiency of the RZ4E engine can be the answer to the worrisome increases in the pump prices of fuel,” he said.
The results only proved that both 2018 DMAX LS and mu-X LS-A 4×2 variants are not only tough, hardworking and reliable vehicles with the lifestyle attitude. Now sporting the new RZ4E engine, these models are also thrifty workhorses. The list of safety features, meantime, is also a steal. Aside from the standard active functions, these two models are equipped with brake assist and the Brake Override System, a notable failsafe measure where brakes take precedence and overrides the accelerator input in case both pedals are accidentally pressed at the same time.