Small engines in a Japanese truck used to be the norm and saw the trucks struggle to perform in the tough Australian trucking industry. The latest trucks from Isuzu are being offered with smaller engines, but with power and torque to burn.
The days of Japanese trucks being brought to market in Australia with the power unit used in small local delivery trucks in Japan, then being sold here in the hope they will be up to the job have long gone. We can be sure Isuzu has a good deal of confidence in the 4HK1 being able to handle anything the Aussie truck owner can and will throw at it.
“There’s nothing like the 4HK1 on the medium-duty truck market today and it really marks the advent of a new generation of power plant,” said Simon Humphries, Isuzu’s chief engineer product strategy. “There’s clear evidence of a global trend towards lower displacement engines across the automotive world as people gravitate towards lighter, more profitable and more efficient engine technology.”
And if there is any doubt whatsoever, there is an alternative on offer. For those applications where the masses are constantly at the upper limit, the six cylinder 6HK1 is also available. The mix of models will probably see the six cylinder specified for vocational applications, while the four should be taken on by pick- up and delivery, mainly urban operations.
The larger engine may also be of interest to truck buyers not using the truck in the highest mass range if they prefer a truck engine without DPF and its consequent regeneration process. Instead it uses EGR plus a diesel oxidation catalyst to clean up the emissions. It could also be desirable if the application requires a high idle time for PTO use or frequent stop/start work.
The torque converter AMT looks set to be something of a game changer for Isuzu. The range has offered both manual and AMT options for some time, but the limitations of the old AMT had led to an increasing number of models being offered with a fully automatic Allison transmission option. The TC AMT is now available on all F-Series models between 10.7 and 14 tonnes GVM.
By introducing a torque converter into the transmission in its third generation, coupled with the simplicity of a standard AMT, Isuzu seems to have found the middle ground. This is an effective and economical gearbox, aided by the better torque and performance of the engine to maintain momentum while at the same time protecting the driveline.
The smoothness of the torque converter being used as the changes are made is obvious out on the road. Going up and down the box seems seamless, so much so that the driver needs to listen carefully to the engine note to detect when the ratios shift.
The alternatives on offer coupled with the four cylinder engine are the Isuzu six-speed manual gearbox or the Allison LCT 2500 fully automatic transmission. Moving up to the larger six cylinder unit sees the manual option go to a ZF gearbox while the automatic offering is the Allison MD 3000.
The choices, as we have come to expect with the Isuzu range, see a wide variety of options to be available. Depending on chassis and desired GVM, the engine and transmission options will change as the Isuzu organisation tailors trucks to keep all offerings well within engineering tested limits.