Heavy goods fleets benefit through vehicle lightweighting

Heavy goods fleets benefit through vehicle lightweighting
Heavy goods vehicles of the future will benefit for lightweighting and engineering design to reduce fuel consumption and emissions and improve safety

Commercial heavy goods vehicle fleets looking to increase fuel efficiency, transport more freight and retain more drivers can look to lightweighting as a key enabler, according to a recent USA study carried out by Trucking Efficiency. The resulting Confidence Report on Lightweighting concludes that investing in weight reduction is an attractive and economical alternative to adding expensive new equipment – potentially saving fleets some US$1 million over five years.

Washington-based, Trucking Efficiency is a joint initiative from the North American Council for Freight Efficiency (NACFE) and the Carbon War Room (CWR) that aims to double the efficiency of trucking fleets across North America.

“When lightweighting is looked at not only in terms of better fuel economy but also improved freight efficiency, it makes sense in a wide variety of applications,” said Mike Roeth, Operation Leader at Trucking Efficiency. “Success for us is getting the $70 billion back into the pockets of fleets and operators, and cutting fleet fuel bills significantly,” he stresses.

Lightweighting investments have already been made by the majority of bulk carriers, and current industry trends make it worthwhile for more carriers to adopt lightweighting technologies. NACFE estimates that over the next 5-10 years the number of refrigerated and dry goods vehicles requested to operate at maximum weight will double and lightweighting can help move their freight more efficiently, resulting in significant fuel savings and reductions in emissions.

One method with a proven track record of helping OEMs achieve lightweighting goals in vehicles of all types is to use aluminium. Research conducted by Ricardo Consulting Engineers has shown that an “aluminium-intensive” Class 8 commercial tractor trailer can reduce vehicle weight by 3,300 lb. For every 10 % of weight reduction, enables up to a 5.5 lb improvement in fuel economy. The study also found that substituting the nation’s fleet of Class 8 tractor-trailers with aluminium-intensive models would cut 9.3 million tons of CO2 emissions annually.

“Aluminum is well-positioned to help move the nation’s freight more efficiently and effectively by providing lightweight solutions in a variety of applications across the heavy and medium duty truck markets,” said Heidi Brock, President & CEO of the Aluminum Association. “With the pending proposal from EPA to further tighten the emissions profile of the heavy duty truck and trailer market, this report shows how lightweighting with aluminium can be part of the fuel and freight efficiency solution.”

The need to trim vehicle weight in the medium and heavy duty truck market stems from a variety of factors. Emissions regulations, fuel economy features and driver amenities have all added an average of 1,000 lb to the average tractor over the past 10 years. As expectations of more pallets per trailer and denser freight, fuel costs and number of weight restrictions rise, lightweighting becomes an increasingly attractive solution.

Other benefits of lightweighting highlighted by the study include:

  • A typical 100 truck fleet would save almost US$100,000/year in diesel costs with 2,500 lb of weight saved per truck.
  • Additionally, every pound shaved off the vehicle’s weight could be recouped as freight.
  • Lightweighting retains its value even if fleets hope to continue shipping even their current quantities of freight.
  • Lightweighting can help offset the added weight of fuel efficiency technologies.

The Aluminum Association’s Heavy Truck Working Group provided partial sponsorship of the lightweighting confidence report with support from its member companies Alcoa, Kaiser Aluminum, Metal Exchange Corporation, Novelis, Rio Tinto and Sapa. One focus of the Working Group is freight and fuel efficiency improvements in the medium- and heavy-duty truck and trailer markets.


Reduced emissions

Similar conclusions supporting the US findings have been made in Europe: For example the European Aluminium Associations’ Automotive & Transport group has conducted a study on the present and future contribution of aluminium for reducing CO2 emissions of articulated trucks. According to the European Commission, Trucks and buses are responsible for around 25% of CO2 emissions from road transport and despite some improvements in fuel consumption efficiency in recent years, emissions are still rising, mainly due to increasing road freight traffic.
In May 2014, the European Commission adopted a comprehensive strategy to reduce CO2 emissions from heavy duty vehicles in both freight and passenger transport. In this context, the European Aluminium Association studied the present and future contribution of aluminium for reducing CO2 emissions of articulated trucks. This study analyses present and future potential CO2 savings when using aluminium as light-weighting solution for trucks and trailers. The study concludes that 1 kg of aluminium in today’s articulated trucks saves 26 kg of CO2 during their whole life-cycle and every additional kg of aluminium in tomorrows articulated trucks would save a minimum of 19 kg of CO2 during their whole life-cycle.


Aluminium for safer trucks

Further pan-European findings lend weight to the case for aluminium: For example the European Aluminium Associations’ Automotive & Transport Group has also conducted a study on passive safety of heavy goods vehicles. This involved extensive collaboration with Forschungsgesellschaft Kraftfahrwesen Aachen on a design concept for a Crash Management System involving a box structure at the front of truck cabins that would absorb energy in case of a frontal vehicle crash. The proportion of lorries in fatal accidents is disproportionate: trucks represent 3% of the vehicle fleet but are involved in 18% of fatal accidents (EU27 in 2008). The study shows that the severity of car to truck accidents could be significantly reduced if an 80 cm energy-absorbing crash box was used at the front of a tractor. A crash could be 15% less intense for cars, therefore reducing the severity of collisions between cars and trucks. Furthermore, designing crash boxes in aluminium can save 50 % of the weight while maintaining the same crash performance.

The following objectives could be met, the study says, with limited costs for transport manufacturers:

  • Between 3,200 and 3,800 accidents involving trucks with less harmful consequences each year (taking as baseline the 7,070 fatalities in EU27 during 2008);
  • Including 300 fewer fatalities per year among vulnerable users following the reduction of blind spots and a deflecting truck cabin shape;
  • Reduction of CO2 emissions between 3.2.% and 5.3% (for a 40t load vehicle), and
  • Savings of €1,500 per year on average in fuel consumption.

Ken Stanford gained a B.Met. in Metallurgy and Materials Science from the University of Sheffield and an M.Sc. In Science & Technology Policy from the University of Manchester, UK.

Formerly Group Managing Editor and Technical Director at DMG World Media in the UK, responsible for editorial in publications including Aluminium International Today, and also the ALUMINIUM series of events, including in Germany and the USA. Particular industry interests centre on sustainability and environmental issues, new technologies, innovations and applications.