To reduce a truck’s consumption, you must first of all have the best technological tools available to you and choose the technologies appropriate to the vehicle’s applications. With Optifuel Technology, Renault Trucks provides a high-performance powertrain on its vehicles, in particular through its robotised Optitronic and Optidriver+ gearboxes. To increase fuel savings still further, there are technological innovations such as OptiTrack and Optiroll but also certain optional extras such as automatic engine cut-off as well as power mode inhibition which can also be added to the fuel-saving features.
Savings and mobility with robotised gearboxes
Robotised gearboxes play a vital role in fuel savings. It is estimated for instance that using a robotised Optidriver+ gearbox (on the DXi 11 and DXi 13 engines) results in about 3% less fuel being consumed on long journeys; a figure that increases to 7% with the Optitronic gearbox (on the DXi 7 and DXi 9 engines). The saving is all the more appreciable in that Renault Trucks drivers also get the benefit of faultless mobility: “We have developed our own gearbox management software,” explains Amélie Debreux, the Long Distance range Product Manager. She adds that, “The trucks have been designed so that the green zone covers not only the area in which engines consume the least fuel, but, at the same time, the one in which the available torque is the highest.”
In the end analysis, electronic management of gear changes provides drivers with the best possible compromise between mobility and consumption, under all circumstances. But to achieve that, an effective gearbox is not enough. You also need to ensure that the gearbox can communicate with and synchronise itself with the other parts of the powertrain in an optimal manner. Insofar as Renault Trucks controls the production and development of each part, it can provide its customers with a harmonious and effective whole.
Over the past few years, robotised gearboxes have established themselves in the market. Indeed, electronic gear-shifting protects the clutch, increases its lifetime and reduces the risk of over-speeding and ensuing engine failure. In addition, it means that drivers benefit from driving comfort, enabling them to fully concentrate on their driving. For construction activities, an off-road mode has been specially developed on Optidriver+. It enables gear-shifting management to be changed when the vehicle has to deal with difficult conditions. The priority is at that point in time given to mobility, but only temporarily. The rest of the time fuel efficiency is all-important. The Optidriver+ gearbox also permits a swinging or rocking effect when the driver takes back control and shifts frequently from reverse to forward drive in order to get out of a tricky situation.
10% less fuel consumed with the OptiTrack system
To obtain further fuel efficiency gains, Renault Trucks has developed innovative technological solutions as part of Optifuel Technology. This is the case for instance regarding the Construction range, with the Premium Lander OptiTrack. This is a system which enables a building site supply vehicle to temporarily have the benefit of extra mobility via two hydraulic motors placed in the hub of the front wheels. A 4x2 tractor vehicle thus becomes a 4x4 vehicle and a 6x2 rigid becomes a 6x4 rigid. Thanks to this system, hauliers can benefit from enhanced mobility in difficult situations (climbing a gradient on a loose surface at a building site, for example) while also benefitting from the advantages of an on-road vehicle. This means being able to carry a heavier payload (with a gain of more than 500 kg in relation to a full-transmission equivalent), enjoying greater driving comfort and above all better fuel efficiency, since the savings can amount to up to 10% compared with an all-wheel drive solution.
A 1% fuel saving with the Optiroll pack, also known as the “controlled freewheelling” feature
In the world of Long Distance trucks, every percentage point of fuel efficiency savings counts. For the Premium Long Distance and the Magnum, Renault Trucks developed the Optiroll pack. Integrated into the speed regulator, Optiroll automatically triggers the Optidriver+ gearbox’s “controlled freewheelling” feature when driving conditions enable fuel savings. The feature thus makes optimal use of the vehicle’s momentum, and can reduce consumption by as much as 1%.
The pack also features soft cruise control, a speed regulator which is more effective and economic on undulating terrain. The driver sets a given speed, and the soft cruise control optimises fuel consumption. It can, for instance, reduce the speed very slightly on certain uphill sections, so that the engine speed delivers the best compromise between torque and output being achieved and fuel consumption being reduced.
Power mode inhibition
Power mode provides an increase in power when a driver is faced with unexpected situations. But the extra power is expensive in terms of fuel. This is why, in order to make fuel use reductions a priority, Renault Trucks offers power mode inhibition as an optional extra for road hauliers whose main aim is to save as much fuel as possible.
Automatic engine cut-out
When at a standstill, with its engine running, a truck consumes about three litres of fuel an hour. “Pointless” fuel consumption which Renault Trucks can save you by automatically having the engine switch off after five minutes when stationary and when the parking brake is on and no PTO is operating.
Equipment geared to saving fuel
Right from the vehicle configuration stage, Renault Trucks offers a series of accessories which contribute to reducing fuel consumption. For example, accessories such as deflectors can enhance the truck’s aerodynamics, adapting the tractor vehicle to the trailer it is pulling and thereby reduce the rig’s drag. But the accessories in question here can also concern optimised side fairings or the choice of specific tyres.
A vehicle optimised for low fuel consumption – Premium Long Distance
With Premium Long Distance, Renault Trucks was the first manufacturer to market a vehicle focused on its customers’ profitability, offering one of the very highest payloads on the market while at the same time reducing operating costs and increasing hauliers’ productivity. From 2008 to 2010, a test was carried out by the German road haulier Fehrenkötter, and after three years of use under actual operating conditions, the Premium Long Distance finished in the gold medal position. The vehicle was crowned champion in terms of savings, since its fuel consumption was the lowest of the six trucks in the running.
A vehicle-plus-services offering optimised for low fuel consumption – Premium Optifuel
In 2009, with Premium Optifuel, Renault Trucks was the first truck manufacturer to launch an overall “product-plus-services” offering focused on fuel efficiency. This optimised offering is built around the Premium Long Distance, which leads the field in terms of fuel efficiency. Configured to consume as little fuel as possible, the truck is employed in conjunction with the fuel-efficiency instruction program developed by Renault Trucks and with the Optifuel Infomax fuel consumption measurement software. Premium Optifuel can deliver savings of 6.4%. This figure has been confirmed by the TÜV, an independent German body. Since then, Premium Optifuel has extended its lead still further by incorporating the Optiroll feature.
Adapting the energy source to usage – diesel, electric, hybrid or natural gas
When configuring a truck, it is important to choose its power source carefully. Apart from Diesel, Renault Trucks provides a wide range of alternative-energy Clean Tech vehicles which open up new horizons for road haulage firms wanting to reduce the amount of money they spend on fuel.
To make “last kilometre” deliveries right in the heart of city centres, road hauliers can opt for the Maxity Electric. A genuine 4.5-tonne small truck which can be driven in France with a “B” (car) driving licence, it is 100% electric and so does not consume a single drop of fuel. In addition, the lack of polluting and CO2 emissions as well as the minimally low sound levels make this vehicle a favourite with city centre residents and one which is also suitable for night-time and inner city delivery runs.
For urban distribution requirements, which entail higher payload capacities, Renault Trucks provides the Premium Distribution Hybrys Tech. This “parallel” hybrid vehicle combines an internal combustion engine with an electric engine powered by kinetic energy recovered during braking and deceleration. The kinetic energy is then converted into electricity which is stored in traction batteries. These batteries thus operate fully autonomously and do not have to be recharged. The vehicle starts in electric mode. Once a speed of approximately 20 km/h is reached, the Diesel engine takes over. This means that it is only used at times when it consumes the least fuel, in other words apart from during the start-up phase. The Premium Distribution Hybrys Tech is the largest hybrid vehicle on the market. It comes in 19 t and 26 t models, and also in bodied, tipper, platform crane and refuse collection configurations. Measured fuel savings which can be as high as 20% !
Finally, for certain applications such as captive fleets or fleets operated by regional authorities, compressed natural gas (CNG) can prove to be a wise choice. For gas-powered vehicles emit neither smoke nor particles and are quieter than their Diesel equivalents. CNG technology is a good match for the uses which Premium Distribution meets. Renault Trucks’ CNG offering comes in two configurations – an 18–19 t rigid and a 26 t 6x2*4 rigid. The offering is principally intended for urban and suburban uses in the distribution, street-cleaning and industrial and household waste disposal spheres, as well as for collections which require equipment with boom arms, such as glass collection for instance.
Reducing fuel consumption is not something to be improvised or imposed. A precursor and leader in this field for many years, Renault Trucks has a global approach to this issue embodied in its Optifuel Solutions.
In order to achieve substantial and sustainable results in this area, Renault Trucks recommends users to correctly configure their vehicles, particularly their mode of propulsion, train their drivers properly, carefully measure and analyse their consumption and then optimise their fleets by regularly maintaining and updating them.
Optifuel Solutions are one of the cornerstones of Renault Trucks' All For Fuel Eco approach, which aims to mobilise the energy of the manufacturer's entire workforce, from the design stage right through to vehicle sales or repair. As a result, it will be possible for customers to be offered concrete and efficient ways of continually driving down their fuel consumption.