It seems that nowadays, off-road conditions exist everywhere and while the 4×4 bakkie brigade is able to take our crumbling road network in their stride, the national truck fleet is getting severely hammered. Isuzu Trucks may just have answer to this predicament with its new 4×4 Isuzu N and F-Series trucks.
OK, so they were not designed with South Africa’s potholed roads in mind but for operation in genuine off-road conditions as is evidenced by their generous angles of approach and departure combined with an optimum wheelbase for added ground clearance while also providing a useful cargo body length.
At 6 ton GVM, the NPS 300 makes a lighter footprint than its heavier stable mate, the 13,5t GVM F-Series FTS 750. Add to this a wheelbase of 3365 mm and an overall width of 1 995 mm compared to 4 250 mm and 2 400 mm of the F-Series, the NPS 300 also has a clear advantage in the manoeuvrability stakes.
Both 4×4 models enjoy the benefit of a limited slip differential requiring no driver intervention when any rear wheel starts to spin , automatic lockup ensures positive traction on both rear drive wheels.
Six-speed transmissions provide excellent grade-ability in first gear when using the multiplication forces of the low range transfer box , for the N-Series this is 80% and 67% for the F-Series. (Figures quoted on full GVM).
A distinct off-road technical feature of the FTS 750 is full-time all-wheel drive. Isuzu says research shows these trucks are not engaged in long-distance operations and consistent mobility, without complex judgement on surface conditions on the part of the driver, is a key factor.
Technology
The entire Isuzu truck range, medium N-Series, heavy F-Series and extra-heavy Gigamax are now available with turbo-intercooled, electronically-managed engines complying with Euro 2 emissions requirements.
Common rail fuel-delivery systems with consistently maintained injection pressures exceeding 1 600 bar from idle to maximum engine speed ensure improved fuel economy and reduced exhaust emissions while turbo-intercooling on the N and F-Series 4x4s eliminate power loss at altitude.
The NPS 300 and FTS 750 develop torque outputs of 404 Nm @ 1500 r/min and 706Nm @ 1450 r/min respectively. Developing Nm at low r/min, these engines have low-end ‘˜grunt’ to get moving in tough underfoot conditions.
A vacuum-air braking system with ABS control is a standard safety feature on the NPS 300 including an engine exhaust brake. An addition to the braking system for this unit is ASR , anti-slip regulation or acceleration skid control.
The FTS 750 is equipped with an air-hydraulic braking system and auxiliary engine exhaust brake while ABS is not standard on this model.
As specialist vehicles, Isuzu 4×4 N and F-Series trucks are set to gain a strong presence in markets requiring the advantage of all-terrain mobility.
A comparative table of key factors distinguishing the Isuzu N and F-Series 4×4 models
|
Isuzu Model |
Gross Vehicle Mass – GVM |
Low range transfer case ratio |
Limited slip differential |
Full time all-wheel drive |
Manual steering axle hub locks |
Centre differential lock |
Option for all single tyres |
| NPS 300 4×4 |
6000kg |
1: 1.842 |
Yes |
no |
Yes |
no |
yes |
| FTS 750 4×4 |
13500kg |
1: 1,913 |
Yes |
yes |
not needed |
yes |
yes
|
