The new engine in the Isuzu F Series shows us how bigger is not always better. When the new F-Series was launched earlier this year with a fancy light and projection show, the story was all about the headlines, new engine, improved telematics, better transmission and new variants. Apart from that, the grille of the trucks has received a facelift and the way the trucks are named on the door has changed.
Approaching the new trucks with a casual eye tells the viewer this is just another new Isuzu. The grille has been changed and the smile at the front is now toothed, but not particularly aggressive. There is certainly clearer information on the door. Gone is the engine specifying badge, replaced by just two numbers; one denoting GVM and the other approximate engine horsepower.
Opening the door reveals the familiar Isuzu cab interior, although the functionality available via the double DIN entertainment system seems to increase as each small change is made in the Isuzu line-up. There is also the new AMT (automated manual transmission) and its controller, which we are likely to be seeing more of in the future judging by the performance of the transmission in this test.
Starting the engine and setting off down the road gives the driver a chance to assess two new aspects; the new four cylinder engine and the torque converter automated manual transmission (TC AMT). On first appearances both look as though they will have a profound effect on the type of truck Australia will be buying.
The new four cylinder engine is the 4HK1. It’s a 5.2 litre unit with a two-stage turbo and intercooler. Available in two power ratings of 210 hp (154 kW) and 240 hp (177 kW), the new engine is a redesign of the four cylinder engine from Isuzu with much improved power and torque. Torque levels are 726 Nm (535 lb ft) and 765 Nm (584 lb ft). The two-stage turbo is all new, the first is a low pressure item and the second a variable geometry (VGT).
Emission control is achieved using EGR and a diesel particulate diffuser. The engine actually meets the Japanese PNLT emission control standard. This means it complies with the highly stringent levels of the planned limits set in ADR 80/04, expected to be introduced here sometime after 2020.
The beefed up outputs signal the Australian arm of Isuzu now believes the power plant is up to the task of handling GVM ratings up to 14 tonnes. The power and torque ratings are deemed substantial enough to handle the task at hand.
Truck manufacturers like Isuzu have learnt over the years to be very conservative when specifying engines for the Australian market. Erring on the side of caution has seen the truck maker going with the higher displacement engine if there is any durability or power concerns.