In today’s economic climate, the prices of most goods are continually increasing; and the cost of fuel for our vehicles is certainly no exception, writes Robert Anderson, Cenex's programme manager for fleet carbon reduction.
It is well known that carrying unnecessary weight in a vehicle increases its fuel consumption. However, by how much has been debated for some time. So just how much money could you save by asking your drivers to stop using their vehicles as mobile storerooms?
In May 2010, AEA undertook research that measured the fuel consumption for a number of vans over the NEDC test cycle while fully laden and empty. The results of this research indicated that the average increase in fuel consumption when fully laden was around 8%, even though the load typically added around 50% to the total vehicle weight. It therefore seems reasonable to conclude that the amount of weight most of your drivers might unnecessarily carry in their vehicles would only have a small impact on fuel consumption. However, the NEDC cycle contains gentle acceleration and in duty cycles with more stop-start and faster acceleration, we would expect weight to have a bigger impact.
It was for this reason that Cenex undertook new research, which for the first time modelled the impact of weight on fuel consumption using real-world driving conditions. This research was carried out on behalf of the Energy Saving Trust, which was keen to utilise Cenex’s unique experience in modelling vehicles over real world drive cycles, to ascertain the exact impact weight reduction might have on fuel consumption.
For this research we used our in-house fleet carbon reduction tool (FCRT), a sophisticated vehicle simulation and modelling software package, to help identify the potential fuel consumption benefits of reducing weight within a panel van and car-derived van. The tool can calculate the fuel usage and the carbon reduction performance of different transport fuels and technology options within real-world fleet applications. It is a computer simulation package and is designed to be flexible in operation.
Using the FCRT, our research compared these vehicles empty and fully loaded on typical urban and rural driving routes (using the Artemis Urban and Artemis Road drive cycles respectively), which more accurately represent realistic driving conditions.
Under urban driving conditions, our analysis found that a typical car-derived van, such as a Volkswagen Caddy, would use around 26% less fuel when empty compared to when fully loaded. A fuel saving of around 5% was achievable with a weight reduction of 150kg.
As for larger panel vans such as the Peugeot Boxer, the difference in fuel consumption was up to 33%, with 3% fuel savings achievable with a weight reduction of 150kg.
It is accepted that not every driver can reduce their vehicle weight by 150kg; however the EST have estimated that if half the van drivers in the UK lightened their loads by 75kg – equivalent to three bags of cement or an empty industrial gas cylinder – they could save a total of around £50 million on fuel each year. This would also result in around 100,000 fewer tonnes of carbon dioxide emissions being released.
How many of your drivers treat their van as a mobile storeroom for rarely needed equipment or parts? By simply educating drivers on being aware of necessary and unnecessary objects in their vehicles, fleet operators can save a substantial amount of money across the year. Drivers should also thoroughly prepare for each job, ensuring that any tools or equipment they are carrying are the correct ones; thereby ensuring no further weight is placed in the back of their vans. Reducing the amount of additional weight in your vans will not only improve their fuel economy, but could reveal that the vans are bigger than necessary, with underutilised space. As a result, you could consider downsizing and opting for smaller, more economical vans which better suit your operational needs.