Commercial Motor takes a look at what we can expect to see fuelling the trucks of the future and how the industry is making preparations (part one of two).

When many of us were starting off in the industry, predictions about the day the oil runs out suggested that it would all be long gone by now.

That has proved to be far from accurate and we’re still finding new reserves of black gold, and new ways to extract it, such as fracking.

Although these reserves tend to be more expensive to access, this isn’t reflected in the price. The average price of a barrel of OPEC crude today is $34.69 (£23), the same as it was in 1980, and a lot less in real terms, $35.52 (£23.69) ($108.74 (£72.51) inflation adjusted).

Global production is still increasing, having risen steadily from a post-Gulf War level of 60 million barrels per day in 1983 to just about 90 million today.

Oil is a finite resource so the search for a replacement will only intensify. The search is not only motivated by the eventual demise of oil supplies as governments worldwide, both national and local, are joining the movement to reduce emissions, especially in urban environments.

Their plans are backed by either outright bans or punitive taxation on higher emissions vehicles. One major issue with governments getting involved is their fickle and short-term prioritisation.

A good example is in the UK where one regime is convinced by “experts” to encourage diesel cars so as to reduce CO2 emissions, then a few years later, another lot get persuaded that CO2 doesn’t matter as much as NOx and particulates.

So what will the fuel of the future be? There are at least as many answers as there are truck manufacturers.

The earliest advances in oil replacement technology are coming from the car manufacturers, and they are to be applauded. However, what works for a 1,500kg car is not necessarily suitable for a 44-tonne truck.

There are three categories of solutions: diesel enhancements and alternatives, hybrids and full-electric vehicles. In the short-term, existing diesel-fuelled internal combustion engines could be made even more efficient, making the fuel go further, but to use a well-worn cliché, the low-hanging fruit has been picked a long time ago.

The latest Euro-6 emission standard and its US and Japanese equivalents have reached a point where any further reductions come up against the law of diminishing returns. They are now at a level where any further reductions would be almost impossible to measure.

Indeed, some observers say that there is now worse pollution created by a truck’s tyre wear than from its engine.


Future legislation is almost certain to take a holistic approach, optimising the whole vehicle in areas such as aerodynamics, transmissions and even operating procedures, but optimisation only goes so far, and in tiny steps.

The most dramatic manifestation may come from platooning, where convoys of autonomous trucks travel at the optimum speed and distance from one another. Although this is technically feasible, and closely monitored, on-highway trials have already begun, we don’t see an early resolution to the legal questions over who is liable when it all goes wrong.

The internal combustion engine doesn’t have to run on the traditional derv, though. There are now alternatives from a variety of sources. Some, like natural gas in its various forms, are still fossil-based and subject to the same finite limitations, while others come from more sustainable base products.

Ethanol is seen as a viable alternative, except that much of it comes from sources that could be used for food production, raising serious moral issues about food for fuel.

The most practical way of making your fuel go further is to use some form of hybrid system. Although the rise of hybrid technology was dominated by petrol/electric systems, this was largely due to its early adoption by Japanese manufacturers who don’t get diesel.

For trucks, we’re still looking at diesel, and alternatives as described above, as providing the internal combustion element for a hybrid system.

Scania hybrid transmission

There are a number of ways of providing the hybrid element, most involving various means of storing electricity generated from kinetic energy that would otherwise be wasted, for example by regenerative charging under braking.

However, other storage media are being developed, including hydraulic, such as Eaton’s Hydraulic Launch Assist system, which releases stored pressure to augment engine power when moving from rest. Mechanical systems, such as being developed by the

UK’s Torotrak, which store waste kinetic energy in an enclosed high-speed flywheel unit and again releases it to assist with acceleration. Both of these types of system typically demonstrate fuel savings in the order of 25% in trials. See part two tomorrow.