Take your foot off the gas

With diesel representing over 80 percent of its energy costs and eight percent of the company’s total expenditure and fuel prices rising, Winstone Aggregates was looking for ways to drive down costs and improve its fleet fuel efficiency.

By adopting a suite of solutions to cut its per-kilometre fuel use, the company says has improved its margins without the need for dramatic increases in cartage prices.

As the country’s largest aggregate company, with 26 quarries nationwide extracting 4.5 million cubic metres of material every year, Winstone Aggregates’ fleet travels around 5.5 million kilometres each year – with a loaded truck and trailer leaving one of its quarries every 35 seconds.

With part funding from EECA, Winstones hired energy efficiency specialist Envirostate to conduct an independent fleet audit. Though the audit confirmed the company was already heading in the right direction, transport manager Brett Horrobin says it helped to clarify a few important areas, such as identifying what they couldn’t control and what they could.

“More of our fleet are now working on ‘premium highways’ — roads that are undulating or steep — like the Napier-Taupo road, or Matakana Valley to North Shore. These roads have a negative impact on our overall fuel efficiency and, while we can’t do much about road terrain or conditions, the report highlighted many other things we can control that will greatly improve our overall fuel efficiency.”

The most obvious place to start was with the choice of power plant, and Winstone Aggregates devoted considerable time researching engine efficiency, identifying a combination of Detroit Diesel and Scania engines as the best fit for their operation. Both options meet the new Euro4 (emission) standards for diesel engines that came into effect on January 1, 2009.

As the company’s fleet is leased, it has been replacing less efficient power plant as each vehicles lease expires, with all but five of the most inefficient vehicles now replaced.

Beyond the power plant, Brett Horrobin says there are five key ways the company has achieved significant savings — and at a very low cost to the business.

Reducing idling time has had a real impact on fuel efficiency, he says. By encouraging drivers to turn their engines off when picking up loads, and better planning journeys to avoid traffic congestion, the company has managed to reduce idling times from 12 percent to just six percent.

Having covers on trucks at all times, both loaded and unloaded, can create energy savings of around eight percent, according to the fleet audit. Loaded Winstone Aggregates trucks are already covered to stop particles from blowing out, so it was an easy step for the company to introduce a policy to cover unloaded trucks too.

Vehicle speed was overall reduced by around 10 kilometres per hour, which can reduce fuel consumption by around 0.25 litres per kilometre, which prompted the company to fit all their new electronic engines with 90 kph speed limiters (which also reduced traffic infringements).

Tyre management for its North Island fleet is outsourced to a specialist tyre company, but Winstone Aggregates operates an internal programme alongside that checks one truck and trailer unit per day for tyre pressure and general wear and tear. Overseas research has found that optimal pressure can result in fuel savings of up to three percent.

The last area is travel planning and management, using GPS route monitoring to minimise idling times and maximise backloading opportunities to reduce overall mileage. For example, a truck taking a load from the Hunua quarry into central Auckland will often pick up a load from either Three Kings or Puketutu Island on the way back.

The company also tries to send trucks on routes or destinations that eliminate the need to travel on congested highways during peak times. Winstone Aggregates operates two trucks at night (there is an estimated 10 percent efficiency gain from transporting aggregates between 6pm and 6am).

Together, Horrobin says, these steps are key to running a fuel efficient fleet and he is quick to highlight that the Winstone Aggregates’ ambitious fuel efficiency targets won’t be achieved without the full support of its drivers. It’s for this reason the company sent its Auckland drivers on a specialist fuel efficient driving practices course.

Making drivers part of the fuel efficiency solution is also why the company’s actual fuel efficiency performance is monitored against targets each month and every driver’s performance (versus the company target) is displayed on the smoko room wall for all the other drivers to benchmark against, says Horrobin.