IS HILUX STILL

THE UTE KING?

We've delved DEEP beneath the surface to see if the first new HiLux in a decade is worthy of hero worship

By Mark Oastler - CarsGuide
Images: Jarrod Barnes & Toyota
17 November 2016
Ten years between generations is a long time in the automotive game, but common among light commercials.

Toyota has a lot riding on the success of its latest NG-series HiLux, in an increasingly competitive Australian and global ute market that forced it to freeze its initial design plans a few years back and come up with something better. Much better in fact, because this is the best one yet and it has relied heavily on big input from Australian engineers to make it happen.

This all-new eighth-generation - the first new HiLux in a decade - has benefitted greatly from six years of development and evaluation by local Toyota engineers, including more than 650,000km of testing in Australia and another 400,000km overseas. That's more than one million km of bump and grind, resulting in a swag of improvements across the range.

HILUX HISTORY

The world's most popular utility is now in its eighth generation after starting life in March 1968 as a 4x2 ute with a small capacity petrol engine.

Since then more than 16 million HiLux single, extra and double cabs have been delivered to customers around the world. In Australia alone, HiLux sales have passed 860,000 units, or five per cent of total global production.

It has also been Australia's best-selling commercial vehicle for more than 17 years and the country's best-selling 4x4 for the past decade. Although 4x4 versions did not arrive until 1980, the extra off-road ability and ground clearance have clearly won favour with Aussie buyers by outselling their 4x2 stablemates every year since 1996.

The HiLux has evolved over the past 47 years into a comprehensive vehicle range that now offers SUV-like levels of comfort, safety and technology, turbodiesel engines, twin-cam and quad-cam petrol engines, 4x4 variants, automatic transmissions and higher specification levels for recreational users. Australian-market HiLuxes are built in Thailand, and account for around 70 per cent of global production.

1968: The first RN10 HiLux was 4x2-only

ENGINE OPTIONS

The previous 3.0-litre diesel has been replaced by new 2.4 and 2.8-litre units, while petrol four and V6 options remain.

There's two new Euro 5-compliant common rail turbo-diesel engines of 2.4-litre and 2.8-litre capacity that are significantly quieter and more fuel efficient with improved torque.

Both engines have a lower stressed 15.6:1 compression ratio (down from 17.9:1 in the previous 3.0 litre) and feature a Toyota-developed variable-vane turbocharger with intercooler, plus a water-cooled exhaust gas recirculation system with a cooler bypass and diesel particulate filter to minimise emissions. The SR5 runs the 2.8, which is what we'll focus on here.

2.8 LITRE DIESEL OUTPUTS

The new 2755cc 1GD-FTV turbo-diesel delivers its maximum power of 130kW at 3400rpm and peak torque of 450Nm between 1600-2400rpm when matched with the new six-speed automatic. When mated to the new six-speed manual, the peak torque is reduced to 420Nm and accessed over a slightly broader 1400-2600rpm range.

So that's a big torque boost of 25 per cent for the auto and 22.4 per cent for the manual compared with the previous model's 3.0-litre (2983cc) 1KD-FTV engine. It should also be noted that with the six-speed auto the peak of this increased torque is accessed in a much narrower 800rpm band than the old engine, which had its lesser 343Nm on tap across a much wider 2000rpm spread from 1400rpm to 3400rpm.

While that narrower band may give the impression that this new engine is more 'peaky' and therefore more difficult to keep in its maximum torque zone, it's not an issue when driving (particularly with a payload) because the six-speed auto's intelligent software manages to keep the revs within the peak torque range regardless of the gear selected.

We note Toyota's reputation for big durability margins remains well entrenched, by reducing the torque output of the manual version by 30Nm compared to the auto. That's because the slush-box with its fluid coupling torque converter can better 'cushion' potential shock loads in the drivetrain.

Official combined fuel economy for the SR5 4x4 is 8.5 litres/100km for the auto (compared to 9.3 in the previous model). That reflects on overall improvement in efficiency, given the new model is more than 100kg heavier in this guise. CO2 emissions are also marginally lower with a claimed 223 grams/km compared to 230. Don't forget, these factory figures are achieved in strictly controlled laboratory conditions; average consumption in a variety of ‘real world' situations is usually a bit higher as we discovered (see On-road section).

INSIDE THE NEW DIESELS

The new diesels are a marked improvement by every measure compared with the old 3.0-litre.

Clearly there's been a boost in combustion efficiency with the HiLux's new GD-series turbo-diesel, but it also has numerous engineering features aimed at reducing weight, friction and noise. The results of these refinements are noticeable from start-up. It's just smoother and quieter.

Toyota claims the 2.8-litre has a maximum of 44 per cent thermal efficiency (or how well heat energy is converted into power) which is at the leading edge of the industry and up to 15 per cent better than the previous engine. Friction losses have also been reduced by up to 28 per cent to cut wear and fuel consumption.
The GD series' electronic direct-injection system has been improved with new solenoid injectors operating at pressures as high as 2,500 bar. That's more than 36,000psi on the old scale. By comparison, your average LPG cylinder is rated at less than 500psi. That should give you some idea of the massive pressures and fine tolerances involved and why the slightest drop in fuel quality/cleanliness can cause havoc with today's common-rail diesels. Toyota says the injectors are smaller and more cost-effective than piezo-electric alternatives, delivering the same level of performance while reducing fuel leakage and the weight of moving parts.

Thermal losses have been reduced by changing the shape and position of the intake ports and increasing the amount of airflow by up to 11 per cent. The 2.8-litre engine has the added feature of swirl control valves in the intake manifold to increase combustion efficiency and reduce exhaust emissions. The new diesel oxidation catalyst is also about 30 per cent smaller, reducing the amount of platinum required.

A newly developed 'film' on the top face of the piston reduces heat and therefore the temperature difference between the top face of the piston and the gas inside the cylinder for more compatible and effective combustion. Frictional losses have been cut by using high-strength but lighter materials to reduce the weight of reciprocating parts including pistons and connecting rods.

The HiLux comes with an extra fuse box in preparation for extra electrical accessories.

The newly designed valve rocker system uses more efficient roller rockers to replace the good old mechanical rockers - or 'rolling friction' as opposed to 'sliding friction' in Toyota speak. That's why lots of race teams use roller rockers, too, because they primarily reduce frictional losses to create more power. Toyota has adopted its own variable-vane turbocharger, which is about 30 per cent smaller than the previous unit with a claimed 50 per cent faster response, to greatly reduce the negative effects of 'turbo lag' on fuel efficiency and throttle response. The strength and reliability of the variable-vane mechanism within the housing (which constantly optimises exhaust gas flow into the turbine wheel) have also been improved by simplifying the manufacturing process to involve the machining of just a single forged part.

Toyota has also left room behind the battery for an auxiliary battery to be mounted.

The thickness of the cylinder head casting has been slimmed down to reduce engine weight. Considerable attention has also been paid to suppressing noise and vibration, with acoustic insulation covers for the head and sump and a more rigid mounting for the turbocharger. The shape of the new inlet ports, EGR (Exhaust Gas Recirculation) port and intake manifold have also been designed to suppress intake variations in each cylinder to improve its overall sound quality.

Features to increase durability and service life are evident, with a low-friction and maintenance-free timing chain replacing the previous engine's rubber belt along with new oil and vacuum pumps.

Engine durability, particularly in hot conditions and when towing, is also improved by a new radiator core with more coolant tubes, optimised fin shapes, coolant flow rate and a larger total heat-dissipation area. The turbo intercooler, now positioned in front of the engine's radiator rather than at the top of the engine bay, is also more efficient in reducing the inlet air temperature, resulting in the highest inlet charge volume for maximum power.

A nice touch is the dedicated fuse box in the engine bay containing a bank of 10 fuses to allow safe connection of accessories to the vehicle's power supply. Given that Toyota is offering more than 60 locally developed accessories for the new HiLux, this also makes sense.